Beside bullied and sexual harassment Snape, James also bullied many students.when he in school.

for Book 6 (HBP) chapter 24: Harry found out that his father had many detentions for bullying other students.

Example: James Potter and Sirius black using an illegal hex upon Betram Aubrey. Aubrey's head twice normal side. That could cause brain damage for life. How cruel they were.

Book 5 (SWM): James even said to Lily: go out on a date with him and he will never lay a hand on "Snivellus again", but in Book 5, chapter 29: Lupin said that James never can leave Snape alone, even after dating Lily in 7th year, still hex Snape behind Lily's back

Book 5, chapter 29: Sirius admitted that James used to hex people for fun, only stopped when he became head boy. What's wrong with James, hurt people just for fun?

Book 5, (SWM): Lily said that James hexes every one he thinks annoy him.

Even James's best friend admitted that he bullied many people.

And James have the map and the invisible cloak, then maybe he can bully many people but no one know this is him and his gang.