According to this, that's illegal, too. Yes, it happens but it's still illegal and actionable. You will find, I think, that many schools are stepping up efforts to prevent that sort of thing.

Update: More Links:

• Schools are responsible and can be sued.
• Some believe Title IX may not be the right approach
• It's not always innocent.
• Other countries are dealing with similar issues.
• It's a very involved issue.

--f