I warned the other account rather than banning them because, even though they've broken the site guidelines badly on more than one previous occasion, we hadn't warned them before.

We've banned your account because you've broken the site guidelines badly on many occasions and because we've asked you more than once to stop.

https://news.ycombinator.com/item?id=20271284

https://news.ycombinator.com/item?id=20098782