Even if the photocopier overwrites the information, it's going to take at least x# of writes over that same data to have all ghost of it gone.
I have recovered files off a system from over 7 years old with our "Recovery" program after formating it. (An old server that we were taking down) This was a heavily used FTP server, the drive was full almost 90% of the time and being overwritten with all new data daily.

Just fair warning to those whom think their data only exists for so many days/months...