So since 10am SLT protesters have been hanging around at the main stage at the birthday site waiting for Philip's speech and showing out signs. I wrote about the issue earlier today and now listened a bit what the actual problem for them is.
So it seems that not griefers are their main issue but teens. So their issue is that LL promised to have a clear distinction between teens and adults and that's what they created the teen grid for. Now according to them this is not the case anymore as any teen can sign up for the main grid without any age verification which might lead to massive sueing and bad press (mySpace is given as an example) of LL and thus might lead to the end of Second Life.
Other people are worried that they might have virtual sex with a kid without knowing it and might be sued because of that. Again others just don't like to hang out with teens.
So that's basically what I've heard there, you can build yourself an opinion. Attached again some photos.
Update: I hardly had a chance to see anything of Philip as I could not log in nearly the whole time but from what I've heard the registration process will not be reverted (surprise). But we will get a field in the profile next week which says if an account is verified or not. He also said that sometimes you need to go the hard way and first changing registration to see which tools you need. And after all abuse report numbers have not been dramatically increased.