Given that the meme is "who do you have a crush on?" the whole thing seems like it's potentially rather nasty.
shatterstripes suggested breaking their database:
Let's poison LJ Secret Crush's database.
Pick a random LJ user and go fill out the form for them. Pick a gender at random, and hit every dropdown, setting it to something other than the default "never crushed". Make sure that they're deeply and openly in love with any RSS feeds or communities.
And, of course, post this in your journal!
I particularly like the idea of giving people crushes on communities and feeds. >:>