To really get your head spinning, what if you used 'strings' on your own dna and you found some interesting ascii segments in there, on 4 billion basepairs the chances of finding something interesting are pretty good ;)
But like another poster said - we are pattern recognition machines. Coincidences, faces, conspiracies and their ilk just leap to the forefront of our attention.... I wonder if their couldn't be a little bit of this phenomena at work in this study? Not read enough of the primary material to see if it's something they've consciously tried to factor out of the experiments
Finding "killroy was here" in your own DNA would surely make you wonder though :)
We are pattern recognizers, feed us random noise and we'll see patterns.
DNA is not exactly random noise, but for this purpose it is probably close enough.