If you want an exact image of 1's and 0's that you determine, forget it. Bits these days are encoded as transitions between magnetic phase boundaries. They also encode the clock data needed to recover the data along with the data. As a result, what's put down on the disk has to guarantee a certain number of these transitions or you loose sync. In other words, you may think you're writing '0000000' but on the disk it's a bunch of magnetic transitions, not a constant stream of the same magnetic polarity. It's not even that a single phase transition translates into either a 1 or a 0; groups of these transitions translate into a group of the actual data bits. Some patterns of phase transitions can simply never be written onto the media by the write electronics in the first place because they would not result in reliable data recovery by the read electronics.

From your description it sounds like the particular virus used to insert the four genes into the target cell couldn't cause a pandemic if they got out into the wild. However, given the knowledge of the four genes needed to cause the change, could somebody create a different virus to both modify the DNA of the target cell and replicate itself? In other words, what are the chances that somebody could create a new disease that essentially reverts the cells it infects back to stem cells? This would obviously be fatal if it just was able to attack skin cells, much less the cells in other organs of the body.

If the level of knowledge and funding to do something like this apparently has a relatively low threshold ("any decent research lab could do it" was one quote I saw from a biologist), sooner or later some nut will do this deliberately as a terror weapon or simply from experimenting with the process in other viruses. If this could be done with a virus which is currently harmless, there would be no vaccine against it and probably none could be developed before widespread death occurred. In other words, does this discovery give someone the knowledge to create a killer virus from a currently harmless one?