Rebecca Watson wrote a great post about a heartbreaking episode of sexist abuse on the atheism channel on reddit that you should read, but this post from Kate Harding hammers the point home precisely:
Finally, if your solution to sexist abuse on the internet is, “Just don’t let anyone know your gender, or see a picture of you, or ever mention where you live” (as one of the first commenters on Watson’s post suggested), you are so fucking awful, I can’t even. It’s not just that you’re putting all the onus on the targets of hatred to change so that bullies won’t have to, or that you’re conveniently ignoring situations, in almost 20fucking12, where a woman might want to have her picture and contact info on the internet for, I dunno, business reasons? For example? And it’s not even that you’re representing yourself as someone who’s clearly more internet-savvy than the lady blogger in question, but you apparently don’t realize that a highly motivated person can pretty easily discover the identity behind a pseudonym. No, it’s that you’re arguing that abuse of women online would solve itself if only women disappeared from the internet.
Oh, of course that’s not what you’re saying! I know, I know. In the scenario you describe, sexist shitheads would know that there were still women out there–it wouldn’t be as though around half the human race had just vanished!–but they wouldn’t know which specific screen names deserved to have their hotness assessed, their gender mocked, their ideas dismissed, and their bodies threatened. So they wouldn’t even need to bother with all that! PROBLEM SOLVED YOU’RE WELCOME.
Know what, dude who thinks this? You’re probably the awfulest. That’s all.