Wouldn't be bad to hide those(as an option - though I find it enjoyable when I spot someone with one and can go ohh a playstation player like me - yay).

As for the actual case(because let's face it they have them now)...
Open up a harrasement ticket with SE and report them to Sony as well. Either SE does something or Sony does(PS Vita/PS3/PS4 all have a report grief button).