Hmm, how much money this scam would potentially generates? I think the salary of an engineer working on twitter would be higher given how fast this scam would be shut down. Would a twitter employee risk their career to this scam?
I would be surprised if it were an engineer, but not everyone who is employed would be an engineer. When I was at Google two fairly high profile incidents were enacted by contractors (one in the IT "TechStop" group and one a data center tech)