Of course the following is about the newer digital cameras from Olympus, like the PEN-PL7 or the OMD-EM1, not about the old OM1 and friends.

The intentions of the Olympus engineers may have been good, but to me if often happens that I move the focus point or shoot a photo by accidentally touching the display. Cycling through the three states of the touch screen icon (do nothing, move focus, move focus and take shot) does not work. When I set this to do nothing (by touching the icon), I always end up with "move focus and take shot" after a while. Obviously I touch the display all the time when handling the camera and I seem to often hit the touch icon.

But you can switch off the touch on the display in the menu settings. The option is in MENU → Custom Menu (the cog wheels) → Utility (last entry in the list) → Touch Screen Settings.

I wish I could permanently set the mode to "move focus point, but don’t shoot", but it looks like that cannot be done. It’s either "touch display on" or "touch display off" without nuances in between.