There are a few kind people who post gifs and a few comments, and as the episode airs sometimes there's some hilarious stuff posted, especially if it's an awesome episode. The "person of interest" tag doesn't move that fast but it moves, lol.

And lol I haven't attempted to read fic for this show. But Reese/Carter is a little popular on tumblr. You're lucky btw because when the show first started many people hated Carter (for obvious reasons). Now things have blown over and fortunately most people recognise her awesomeness.