It's in memory of the teens who lately likely killed themselves because of extensive bullying over their being gay. But more importantly, it's about showing others in the same situation that they're not alone.
I don't have the time to give you details, check the links and google if you're curious.

facebook page: http://www.facebook.com/event.php?e.....819&ref=ts
News article with briefing: http://www.bu.edu/today/2010/10/19/.....how-solidarity