At least when a ganger beats someone up for 'dissing him' there's a logic to bragging about it, the crime was part of a greater motivation to be feared and respected and that requires advertising. Ditto, someone forgetting to wear gloves during a robbery is guilty of "Stupidity by Oversight" and dumb things during a crime can be partially excused by a need to rush or fear, adrenaline, and anxiety clouding thought.
These are like taking an ad out in the newspaper "I, Jon Smith of 314 Pie Ave, engaged in aggravated assault yesterday afternoon on a homeless man in Grove Park, using a baseball bat in my trunk."
Though it does strike me as a great way to frame someone.
It really is.
I wonder if it's partly because in some of these cases they don't look at what they've done as a "crime" per se, but just as some annoying/quirky/dumb/funny(?) thing that happened to them and exactly the sort of thing all their social media followers would love to hear about? Part of a larger trend of social media narcissism and the filter that only makes things important/interesting based on how they affect one's self, paradoxically combined with general internet anonymity and the expectation that ones friends will agree with and be loyal to you.
Or, they could just be morons 
Well if you look to idiocy as a cause you'll rather fail to find evidence to back the claim, Lord knows there's always a surplus of it lying around at bargain prices, nor narcissism for that matter. Still I have difficulty seeing the anonymity aspect from social media, FB/twitter/etc, because even under an assumed name, a handle, you're not really anonymous anymore than any regularly used pen name is in terms of being attached to that identity and wanting to preserve good opinion of it. You've definitely got the remoteness aspect of anonymity, people say stuff on the net they wouldn't say in person because it might get them punched, and that probably factors in, but you could be on to something with the flavor of encouraged egocentric commentary of these places. They grant a sort of apparent privacy you normally only get when alone with people close enough to look the other way if you admitted to felonies while letting you do it on a stage before a big audience too. Weird, but still fundamentally dumb.
It kind of reminds me of how some celebrities get when they can wallow around in debauchery and spouting off their under-thought views before applause from their worshipers for the behavior and opining. Has social media given us a hundred million rock stars?
- Albert Einstein
King of Cairhien 20-7-2
Chancellor of the Landsraad, Archduke of Is'Mod
