Is it quite simply a relationship measure ie censorship in Iran vs we do not give a fuck what you say in the US we can ignore you any way, main stream media says so, again and again and again and again an nausea. So they basically censor you internally unless you say what they want to hear versus blocking you from 'hmm' listening to other people they do not want you to listen to.
For the likes of Iran that means switching from a IP blocking system to an IP allowing system ie all IPs are blocked, until they are given permission for access. Than all IPs are monitored for traffic flow to see if those traffic flows are in accordance with expected usage patterns for the particular IP holder, if the exceed that significantly than likely an alternate traffic route for broader traffic.
Of course if you tell people, you are going to bomb, bomb, bomb Iran, again and again and well, you get the picture, they are going to get pretty seriously paranoid. Especially when you have idiots, mind you elected idiots, wanting to use nuclear weapons and kill every man, woman, child, grammy, gramps, puppy, kitten and even budgerigar in your home town, well, they are going to be checking every bit of data, every bit of everything they can.
Never to forget, we all know what up tight kind of dicks religious types can be when it comes to blasphemy of any possible interpretive form, from challenging gods chosen the only life in the entire universe (second only to god mind you), evolution is evil and what ever else flat earther nonsense they want to promote (see, hint, hint, there is a comparison to the religious nut USA right(snigger) in there, a secular state trying to become a religious state versus an actual religious state). The idea not being to take away from what one country is but a reminder of what another country is becoming, thanks lead poisoning (may that particular dick rot in the hell of strangling beds, not that I believe in a Hell of that form or pretty much any other beyond what we allow a bunch of greedy psychopaths create right where we are now).