I work for a company that sells and supports software for Veterinarians. A very large majority of Veterinary clinics have a "Clinic Cat" who lives at the clinic full time.
I can tell you in the 10 years I have worked there, that it is not common at all for a clinic cat to do some sort of damage to whatever record(s) were open at the time.
I have two cats myself, and luckily, I don't have any problems with them laying on the keyboard. But, when I asked a Veterinarian one time about how to proactively keep a cat out of somewhere you don't want a cat, and he gave me the best advice.. He said "Whatever the deterrant, it needs to be god that acts it." Meaning, if you want your cat to stay off the kitchen counter, the mere act of you spraying your cat is not enough. Because then all the cat learns is not to be on the Kitchen counter when you are around with a spray bottle.
Funny stuff! I won't be buying it, and I likely won't be promoting it, but it does have some merit for people that have cats that seem to like the massaging attributes of a Keyboard.. :)