[number6]

There was a good talk some years ago at some of the CCC events where some guy found out that scanners sometimes change numbers on forms.

[kiliankoe]

It's David Kriesel's infamous talk about the even more infamous Xerox bug.

Talk: https://media.ccc.de/v/31c3_-_6558_-_de_-_saal_g_-_201412282...

Bug: https://en.wikipedia.org/wiki/Xerox#Character_substitution_b...