I used to work at Realm (the mobile database company). In order to keep an eye on what was going on, there was a Slack integration that reposted any mention of @realm on Twitter.

One morning, we woke up to a #twitter channel full of very nearly porn. Young men, scantily dressed, flexing their abs and flashing smiles at the camera.

Turns out someone added a bot on Twitter that would repost things from Instagram to Twitter, except that Instagram allows dots in usernames and Twitter didn’t. I think the IG account was @realm.of.beauty, which was promptly understood by Twitter as @realm.