Oh no. More people are mad at Justin Bieber! What happened this time?!

It turns out that Bill Clinton wasn't the only one miffed by Bieber's bucket-peeing incident. A custodians' union is furious with the Canadian superstar for basically making the job of one of their own a lot harder. Because, uh, it's hard to clean a floor with a urine-tainted bucket.

TMZ reports that 32BJ SEIU, the largest property workers' union in the country, is steaming mad at Biebs.

"Unfortunately, people are often oblivious to the fact that workers like our members are faced daily with the consequences of such thoughtless acts," a rep for the union said.

"[Bieber's behavior] serves as a stark reminder of the essential jobs that building workers perform and the very difficult conditions under which they perform them. We welcome a heightened awareness of workers' dignity among young people, and hope many will be moved to work for economic justice."

It seems to be a sign of entitlement and ignorance when people treat service and custodial workers poorly -- it's important to remember that someone's dad, brother, uncle -- a human being -- is performing these jobs. And it's a lot easier for them if they can do their work without a rich pop star peeing in their supplies.

Here's hoping Bieber learned his lesson!