Here's another great case of why it pays (literally) to know your rights as an employee
After submitting a request for a day off from work so he could go see a concert, this guy was puzzled when his bosses responded with weird implications that his request was somehow offensive but never actually says "No." His request was made well in advance, so there was really no reason to not approve it. What follows is seriously wrongful termination and well-extracted revenge.
If I had to guess, I'd say he probably should've never included the actual reason he wanted the day off and just said he needed the day and that's it. Either way, knowing his rights definitely came in handy.