run (a)foul ofsomeone or something

fall (a)foul of someone or something & run (a)foul ofsomeone or something

to get into a situation where one is opposed to someone or something; to get into trouble with someone or something. •

Dan fell afoul of the law at an early age.

•

I hope that you will avoid falling afoul of the district manager. She can be a formidable enemy.

•

I hope I don't run afoul of your sister. She doesn't like me.