Because the other twitter terms and conditions on harassment are so well policed. That some people are concerned about screenshots instead of bullying, harassment, etc that we see every day on the platform is quite something.
Well, you often find screenshots ARE used for harassment in as stealth retweets that make it hard for the original poster to counter the re-contexting and perversion of what they wrote.
That happens all the time, so yeah - it is a tool used to bully and harass, used all the time upon twitter.
