How do you prove that "Multi-Accounts" are actually different real people?

So me and some of my friends accounts got banned presumably because we all used our school wifi to play at the same time. So I asked for help in a thread and I got replied with an email saying that I needed to find a way to prove that all the accounts were different people. So what are some ways to prove this because I need to get unbanned and get back to my games before I go inactive.