drivebyacct2 - your account has been dead for about 100 days and 200 posts, basically no one can seen your messages unless they have showdead on. Here's the "offending" post that you were banned for https://news.ycombinator.com/item?id=5982741 (hint - the ban is completely unjustified)
http://openaccess.uoc.edu/webapps/o2/bitstream/10609/14761/6...
http://www.computer.org/csdl/proceedings/ares/2009/3564/00/3...
As far as I know, QR-TAN is being used in Germany for authentication by a number of banks.