Is deviant behavior illegal?

Some deviant behavior is illegal. Some is just annoying. 'Deviant' covers a lot of territory.

For example, a California law classifies homosexual behavior as deviant, but homosexuality is not illegal. Breaking into drug stores is deviant, and is definitely illegal.

'Deviant behavior' is a sociology term that simply means that one's behavior is outside of social norms for that community. Thus being the only practicing Jew in an otherwise Christian community might be called 'deviant'. Riding a motorcycle when 98% of the community drives cars is deviant. Taking advanced placement classes at school and going to college when all around you are dropping out is deviant. None of these things is illegal (we hope!) but all deviate from expected social norms. There are many other examples.