Currently I work from home two days a week, and go into the office on three. (Next year I intend to try and reverse this, going in two and working from home three. I'll play by ear as my line manager tends to more of a Marissa Mayer view to working from home!).
Looking at some of the points you raised;
High-bandwidth contact with co-workers. In the team I'm in there is one other at the site I work at. The rest work in different offices or at home, so we hold meetings via Lync (Skype for Business). That really means that even for the chap who works in the next desk, most communication is done via the laptop with the headphone on (although when at home I dump the headphones!) Also, liaising with other teams is always done via Lync, as none of them are based in the office I am in.
Security of documents. I find most (well, all) documents I use are electronic. Locally held - it is a corporate standard that all laptops have the hard drive encrypted (with BitLocker). When connecting remotely for secure documents, we need to connect via the corporate VPN.
Staying focussed. Surprisingly sometimes I find less distraction at home than when in the office (no background office banter). Also, given that Lync gives your status (available, away, busy, in a conference call, etc), others can 'keep an eye' on you. (And vice versa - I'll usually try and ping someone when not busy).
There are other advantages for me; not spending 40 minutes commuting each way, and saving fuel for the car, and I can be around for deliveries etc. OH, I'll have to heat the house while working, but as my partner is usually around anyway, she would heat the house in any case.
Finally, as to the decline of Slashdot. Yes, I must admit, I don't think I've see a mention of or a link to goatse for years!