Even with the move by many sites of having to pay to message, there is still a huge problem with the experience for women dating online. Very few of my female friends even want to try it, given the horror stories they've gotten from others. A Sadie Hawkins approach would be interesting.
And yeah fellas, I know it's not all of us that send unbidden wang pics or do those overly aggressive creepy PMs and then flip out when someone has the audacity to exercise their free will and say no. But there's enough that do that it poisons the whole experience. And if you think the problem is exaggerated, read any of the numerous articles done by guys who also doubted how bad it was who posed as women on dating sites - it's revolting.