Why? Because there are underage people in this forum.
I'm not aware of laws in other countries, but by Estonian laws it's illegal to expose sexual content to children under the age of 14 and I believe there is at least one user who is younger than that. And possibly some guests also.
This made me shocked. In UK sexual content is strictly 18+ only xDDD 14 is too young. But I guess we all have different customs.
What gets me is that there's a user younger than 14 on a fucking X Japan board. Seriously, that's not OUR problem, that's his/her parents' problem. Shouldn't we just ban users under a certain age? If you're under 13 or so you shouldn't even be an X fan anyway.
Edit: No, I'm not being an elitist. That said, the lyrics and stage performances and publicly known lives of the band are NOT appropriate for children (seriously, in the US, displaying the VV cover itself where someone under 18 could see it is probably technically illegal, for example) and I see no reason why we should have to make the discussion and fandom of something inappropriate at least for preteens somehow child-safe.