FMF programmer as a tach?

Ever noticed when your FMF programmer is just operating it operates like an LED tachometer? Has anyone tried just marking off the RPM each dot represents and then mounting the thing somewhere visible?

I've heard people discussing this before.

The down side is your programmer is highly visible which then makes it an easy target for thieves and vandals.

I live in a city with a high crime rate, several ghettos, etc... Never had anyone mess with my vehicle but I'm also new to bikes. Is people messing with bikes a big issue? I get a lil paranoid at work and look out my window to make sure a disgruntled client hasn't pushed my bike over in the parking lot.