My power? Total access to entire VISA and Mastercard databases of real life citizens credit cards/debit cards. The US company I wrote an entire solution (not just a simple application) also had a part where processing payments was a requirement. Read the user CC, take his credentials, put it in database, start transaction pre-authorization process and later finalization. So to protect the user data from prying eyes I've encrypted the CC data that was read by the magnetic card reader. But for proof of concept I used a simple encryption scheme, which was never meant to be used in production. Countless mails were exchanged between me and the manager regarding the encryption scheme, to upgrade to a modern one, like once per month. Nevertheless this weak encryption entered the production despite my many, countless by now, warnings. Eventually things fallen apart between the upper management of the company and my manager and civil suit ensued. In the end, FBI was involved too and I had to write a affidavit to them regarding this. Offered all my mail exchanges to them which proved that while I was not an US citizen, I had more privacy concerns then the usual US citizen and businessman. Dunno what happened in the end, as I exited the project around 2014, but looking at their site it seems that my code is still in production. Talking about why so many holes and security fails happens, I know first hand how "careful" the average US manager is with sensitive data.