I have recovered Twitter accounts before - and I don't advise going blackhat. In my case, my employer wanted an account which was inactive. We reached out to o

I have recovered Twitter accounts before - and I don't advise going blackhat. In my case, my employer wanted an account which was inactive. We reached out to our brand partner (I think) and discussed it with them. They didn't tell us what methods they used to verify the account was dormant, but they did ask us to prove our trademark etc. A few weeks later we got the account. Now, that's with a fairly standard trademark dispute - it will probably be harder if you don't have a tm.