I've never experienced problems with people bothering cross-gender roleplayers... maybe I just haven't been active enough, but I hope this doesn't escalate into anything big. I myself have been roleplaying a lot of male characters for as long as I can remember, despite being female in real life. I reserve female characters for my own individual writing for some reason...
One thing I noticed, though, is that many real authors are "cross-gender roleplayers" if you want to call them that. I also noticed that manga artists in particular are
really good at telling stories about people of the opposite gender. My favorite manga author/artist is a female in real life, but her characters are almost exclusively male, and yet her drawings are very well developed and the stories she writes are just amazing.
So... yeah, I don't have a problem with it.~ After all, your characters are
your characters, so you should be able to do whatever you want with them, whether that's feed them chocolate for the rest of their lives or throw them off a cliff.