This was not vandalism, but I can see why you might think it was. Originally it explained that this scene took place while Ben Stiller's character is high on heroin. While the movie is primarily about heroin addiction, this particular scene is Ben Stiller's first experience with Crack. Originally it said he was high on heroin, which is incorrect, the character was high on crack. He is also just getting out of an NA meeting, so it's clear that he hasn't done heroin, so it would be incorrect to say he is high on heroin and crack. He is only high on crack, and I changed the Wikipedia entry to reflect this. This is the only change I made. 

 The characters smoke crack in an empty building and get particularly amped up and throw themselves repeatedly at the window to the soundtrack of "Smack my Bitch Up."