I didn't know whether to put this in Biology and Medical or in Programing and Computer Science so I am putting it in General Discussion. This article from Wired describes U. of Washington group that has produced a piece of DNA that when sequenced in a particular sequencing machine can produce a buffer overflow which would allow malicious software to take over running the computer. The article describes their approach, some problems they had, and potential uses much better than I could. To me the most interesting use mentioned was to put such a sequence into an engineered organism to make it more difficult for someone to sequence their engineered organism and reproduce it. Someone has already encoded a piece of video in DNA sequence, so this is just another step in that direction.