My guess would be, the same strategies, every repressed community would use since ever.
As for why governments don’t use net logs, my assumption is, that those are not what they are after. Meeting might not be illegal, just same sex acts which are needed too be “caught in the act”.

1. I’ve read an article long time ago from an expat in, I think Saudi Arabia, in which he described how he tested grindr and got a match. When meeting with them, he got a bad feeling and stepped back.
2. There’s a a (sci-fi) novel with that premise, called “ABC Zhang”. It basically used the points, what others have told here: Mostly secret signs, that those who know, know.

I was too late for that, unfortunately and got <lastname>.<town> which also some people don’t comprehend.
Although it’s the capitol and there are sites from public services which use that TLD as well.

What genuinely pisses me off: Prior to that I got <lastname>.name, and there are sites, which refuse to accept it as a valid TLD when I try to register with them.

Edit: I got <lastname[with umlauts]>.<countrycode>, tho as this was available, but those don’t work that well. Or didn’t, when I last checked.