Re 'Wouldn't it be much more efficient to just eliminate the polygraph altogether?"
Not if your selling and using the kit at a state and federal level.
The UK and other nations know you have to look at a persons life story, interview parents face to face, extended family, friends. School, local courts, chased down old paper records and build up a real generational life story of reading material, internet use, political ideas, faith, links to other nations, links to other nations faith, cash flow.
The US finds this to be hard work that is stuck with cleared gov staff - no private sector profits. So they have passed testing onto a person doing a test in a chair.
At best they watch your reading habit on the internet, do some digital database searches and very carefully note what your reading before the test. A rapid spike in internet searches for "polygraph" or an order for print books on 'polygraph" before the test is noted.
The rest is just time saving questions about your life, reading lists, political connections, family with the cheap digital review/state federal database search as a guide.
The average person sees a complex medical device and the charm of an interviewer hinting they know the person is feeling a certain way and want to "help".
That the job is great for them, but they have to help with a second or third test and really open up, the 'feelings' aspect.
A real spy knows that they are loyal to, faith is and what the truth is - they have no issues or feelings to mess them up on the day.
An average skilled worker with a lot to offer will over think the questions and might fail. A huge loss for the nation over decades.
The UK thought hard about this in the 1980's and seemed to understand what a real look into a persons life was about vs a digital search and perfect interview skills on one day.
The calm spies stay in, the good useful people mess up and are not considered.

The use of slang, street smarts, been part of a hidden culture, keeping that side of you hidden and having traveled the world might be seen as useful.
Or to pick out a person who is not part of that culture very quickly.
The other aspects is cash flow, law enforcement files and blackmail over things you might have done to enjoy that expensive activity.
It really depends on what part of the gov found you or who you face in the interviews.
Some are deeply devout teetotaler other staff might be more world wise and want people who can fit in around the world.
Signals intelligence at home facing blackmail vs an understanding of human intelligence in the field globally.

Re "Point is, if they want you on 'a list', they'll put you on the list, no matter what you do or don't do."
Reworking the old Soviet "owning a western watch" joke:
Three frequent flyers in a military prison get to talking about why they are there.
"I am here because I always got to airport five minutes late, and they charged me with sneaking in", says the first.
"I am here because I kept getting to airport 2 hours early, and they charged me with spying" says the second.
"I am here because I got to airport on time," says the third, "and they charged me with owning a watch."

Thats interesting AC but recall the FBI infiltration program called Patcon (Patriot Conspiracy) around 1991?
The laws, funding, interest was always ready. This new more simple legal listing is just a new next step to gather more people onto new and existing databases.
Patriot Games
http://www.foreignpolicy.com/a...
If you want to go back further you had Project MINARET http://en.wikipedia.org/wiki/P...
i.e. "watch lists" of American citizens around 1967 and 1973.
No judicial oversight, no warrants for interception and even got some UK help too :)

Re:"Face it, this site and it's users aren't even on their radar."
Yes we are AC
Recall Quantum insert? "GCHQ Created Spoofed LinkedIn and Slashdot Sites To Serve Malware"
http://news.slashdot.org/story...
http://arstechnica.com/tech-po... (Nov 11 2013)
We are of interest to some part of the intelligence alliance comprising Australia, Canada, New Zealand, the United Kingdom and the United States. What one nation finds is shared with the other 5 :) (and a few other nations too)

Re Since when is Tor popular?
Think back to the mid/late 1990's as the start point for some onion routing topics.
Naval Research Labs Review had the 1997 paper "Private Web Browsing".
Would early/mid 2000 be another interesting time? The funding, grants, press where in place by 2005. More grants over 2007-2010+

Follow the funding back in the day (Office of Naval Research and DARPA), understand the funding for the huge costly, fast exit nodes in the US early on.
The origins where for open source intelligence gathering by the US mil and the US gov support of "freedom fighters" spreading democracy.
The main issue early on was any user of the tech would be seen as a tool of the US gov. Not good if emerging human intelligence stands out on any telco system.
How was this set back to be fixed? By flooding the network with diverse users globally and offering free bandwidth, better speed and pushing the an open source grassroots technology front.
The press, dissidents and whistleblowers, all kinds of sites started to spread news about wanting to help people the in repressive countries.
ie a large group of users had to be created allow gov users to hide and help with the node/relay.
Carefully crafted news dropped the military and intelligence origins and pushed the press, First Amendment, dissidents, protected speech side.
Follow the early grants back ie "Pass-Through" funding.
Terms like '“Basic and Applied Research and Development in Areas Relating to the Navy Command, Control, Communications, Computers, Intelligence, Surveillance, and Reconnaissance.”" seems to be floating around.
Finally we got to Snowden and the Stinks page. "Critical mass" - the users are all on the same network, and we are back to the fast exit relays question.
Follow the few law enforcement stories, if you have all data moving out of a network, around the world a few times and then back into the same network?
Its simple to find the in ip, back from the message sent. We also now know that the "internet" in some countries is a known network Tempora https://en.wikipedia.org/wiki/... and XKeyscore http://daserste.ndr.de/panoram...

Thats a lot of cash to just spend on letters and a database. The letters get tracking and logging started within a legal gov framework. Someone seems to see a long term plan with the letters and logging funding. The chilling effect of just knowing your in a database and all your net use is been reviewed? Interconnected local databases? A digital version of the classic anti-social behaviour order (ASBO) at a 'community-based level?
That could see a vast network of watching, logging, reporting and costly face to face meetings with some 'injunction' that flows to a criminal offence if breached.
A lot of free support from tax payers for a new more very local ACTA :)

A per year quota that uses your details as the only unique information? Your address, isp can change but the count stays with you as the person who signed up with that isp and ip as found.

Yes the 4 letters show a history of infringement and the isp's can show bandwidth use too. Its the legal cover for the hard part of traditional cases for free via a stored database of letters sent.
Some nice political cover and colour of law. They only want to educate you with warnings.
Its the lawyers that take the final step to seek an identity. The gov and providers can walk away from any long term logging questions. Months of stored logs are just for the 4 letter compliance.

AC its just post ww2 branding. When the Soviet military looked around for people it could trust it had to find people who where not killed by ww2 "Fascist" Germany and would want to support East Germany. A bit like the Neocons/Trotskyist in the USA - you work with what you have and shape it over a few generations.
Fascist as a slogan solved all the generational ww2 problems for the emerging East German. Every old person was tainted by it. The next East Germans could be seen as safer as they where shaped by the new gov. In this role of undoing the harm "Fascist" Germany had done to Germany, wider Europe and Soviet Union great care was taken with domestic branding to make young and old understood what the price of rebuilding from rubble was all about - stopping "Fascist" Germany from reforming and going to war again.
The old people just wanted to forget the war and rebuild, the young people on average thought a new nation not at war was a nice change considering what Germany was like.
So to an average outside person looking in, reading books and picking up words you would see the terms "Anti-Fascist" a lot. You would see aid to Africa/Asia as been socialist. You would read about East Germany spending vast sums on support to back "socialist" revolutions, science, sport, space.
Deep down the Stasi knew the truth. The Soviet Union was paying real cash to rebuild East Germany, they where always going to be in debt, a post ww2 political bargaining chip.
The slogans fooled the West, the public, a few AC's on slashdot and provided nation building. The Stasi understood reality they where in - they needed real hard currency, needed to rebuild and needed to project a nation of science, wealth, sport, 3rd world aid, space science, nuclear power... but had no cash, just huge loans and some export deals with huge sneaky Western brands seeking very cheap workers. The Stasi also worked out one vital fact. The Soviet Union would never protect them long term, East Germany was for sale to the West. Price was the only question. So the Stasi worked hard to keep their power knowing their nation was all they had. Anti-Fascist aspect kept Russia happy and Russian support flowing, "socialist" worked well in their part of the world. The rest is just West Germany playing its own games with the US and UK for extra support. The real "Fascist" escaped with Operation Paperclip https://en.wikipedia.org/wiki/..., worked without issue in West Germany or at a low level faced tame courts many years after ww2.
In the East Germany they just replaced the old uniforms, found new songs and added new colors to the mass rallies with new "socialist" books to quote.
There is often a lot more behind terms like "Anti-Fascist Protection Rampart" than just found in "Cold" War history books AC.