"Attention-seeking shut-ins with nothing better to do than pretend they’re sociopaths", what's the meaning of this phrase ?
"This idea has two merits. One is that people who are held accountable for what they do and say are less likely to do and say repulsive things. (There are exceptions, of course, but they tend to be professional comedians or radio talk show hosts.) The second one, more crucially for Facebook, is that it no longer has to take the heat for attention-seeking shut-ins with nothing better to do than pretend they’re sociopaths."
Someone who is 'attention-seeking' wants everyone to look at them. Think of a two year old in the room.
A 'shut-in' is someone who shuts himself in his room, meaning he doesn't get out much.
'Nothing better to do' is a phrase that means they have nothing else to do or they are bored.
So this sentence means:
"bored people who don't get out much who only pretend like they're sociopaths"