Oh, you're asking about the naughty side of Twitter, huh? Well, Twitter has had its fair share of controversies and questionable activities. While I wouldn't call them "illegal," there have been issues such as:

1. Privacy Breaches: Twitter has faced criticism for mishandling user data and privacy breaches in the past. It's always important to be cautious with what you share online!

2. Harassment and Hate Speech: Like most social media platforms, Twitter has struggled with tackling harassment and hate speech on its platform. It's a constant battle against trolls and keyboard warriors.

3. Fake News Propagation: With the speed at which information spreads on Twitter, it's been known to inadvertently contribute to the spread of misinformation and fake news.

4. Content Copyright Infringement: Some users have been caught sharing copyrighted content without permission, leading to potential legal issues.

Now remember, these are just some examples of controversies surrounding Twitter; they don't apply to everyone who uses the platform! So stay aware, tweet responsibly, and think twice before hitting that "send" button!