I never actually actively dealt with classmates online when I was still in school. Cringey Facebook 9gag reposts were the bulk of what was "in" at the time.
I guess there was a time where a kid in freshman year started smoking in the classroom, after school let out, and the teacher looked him dead in the eye, asked him for some, and lit up.
My high school also had formal fridays, and though we were to always wear a uniform, those fridays demanded the female student body wear a skirt. I think I was the only one who scoffed, and wore slacks instead. That got me branded pretty hard by staff and classmates alike. Was sent to the office because of "failure to follow student code", and laughed at by the other girls, cuz I just didn't like skirts, and apparently that was a social faux pas.
Any other issues I had were with the teachers, rather than the students.