I remember a practical that failed -- or I guess you could say that it succeeded too well. In Philadelphia, 10-15 years ago, a man decided to play a practical joke on his best friend. He took out an add in the "help wanted" section of the Bulletin, advertising job openings for demolishing houses. Applicants were to meet in front of the site at 6:00 AM Saturday morning. Naturally, the site was the friend's house. The perpetrator imagined a couple of hundred men waking up his friend and asking to demolish his house. Alas, the friend was not home. Another problem was that this was during a recession, with high unemployment. About 2,000 men showed up. It was apparent that only a small percentage would be hired, so a few decided that if they could present the employer with an accomplished deed, they would be the ones to get the jobs. Everybody joined in. A few minutes later, they sat down to await the coming of the employer.
I can't remember what happened after that, if I ever knew. I imagine it got pretty unpleasant. It made the evening news.