Pokerstars - Find a Player.. some players hidden?

So I play a lot on Pokerstars..sometimes I like to know how many tables someone is playing, because sometimes it makes a difference in play style.. sometimes i also like to track down the loose players at my table and make as much as I can from them no matter how many tables they're on...
So heres the thing. Sometimes I'll go to 'Find a Player..' search for a player's name who's sitting at the table with me, and even when i spell their name Case Sensitive, it says 'Player not Found'. Is there a way to hide yourself so people can't look you up? Or is it just a Pokerstars Glitch? Give it a shot sometime when you're playing at a tourney or cash game, almost 1 out of every 10 people I look up says 'player not found' even when I'm playing with them at the time!

Options, hide from search feature. I'm one of the hidden.

Thanks D'wilius, figured there must've been an option. That makes sense especially for people who have a lot of enemies (not saying you, but you know what I'm talkin about)