"I built a tool to allow people to copy corporate data so they could find a job easier."
To be fair, it seems like something you should only do if you don't care about getting fired and if you're already on the way out the door. Unless you're migrating from one email provider to another and your company isn't migrating all the data, most companies are going to take offence to that.
He is suing Twitter, I wouldn't be surprised if he lost because Twitter will successfully claim he wrote a tool to bypass security and allow people to steal trade secrets.