I'm not creeped out easily...but then again I don't really worry about that much. It's not like I try to be anything more than professional and presentable in public, and I don't try harder than that to attract the other gender.
I've probably creeped a few people out online, but mostly by accident...and sometimes they don't always react nicely so it explodes in my face. It's not like I'd stalk anyone online either...just that sometimes ya know...something comes out the wrong way or things get a little closer than comfort allows. Yeah...I'm not always social person so I'm inclined to make awkward mistakes at times. ><
In reality, probably not so much...because I'm actually quite shy. The "Goes on about their own business" kind of person you notice, and don't usually worry about unless you're just really paranoid.
I've never actually been told that I'm a "creepy person" outright. People online, mostly friends, have commented on how some of my behaviors could be "taken" that way, when I make an awkward mistake, but in those cases that was purely a friend watching my own better interests and I was able to fix those problems pretty quickly provided that the person doing the pointing was discreet about it. Even in reality I make sure that people who are pointing out little embarrassing things I might have missed are discrete, if they blab it out loud I give them a chewing for it. I certainly try not to be "creepy" in any means...sometimes to the point I worry about it a little too much, but sometimes despite best efforts the occasional awkward slip-up happens