I am trying to place a sensor or switch on each corner of some desktop PCs so that if they are lifted an event is triggered like locking the computer or encrypting it.
So far I have considered small round load sensors mounted with adhesive between the bottom of the case and the rubber feet that would be on the bottom to help with vibration and avoiding skidding. If the PC were lifted at least one of the load sensors would so indicate this and a small Arduino or similar would be triggered to cause the event on the PC.
I have also considered buying over-sized rubber hemisphere feet carving out space inside for simple momentary tactile switches so that the tip of the actuator sticks out enough through the bottom of the feet that the actuator plus rubber discs attached to the switch points would be present and thus with the four feet wired in series as NO would disconnect if lifted, again triggering an event for defense from the same kind of board.
I've mostly ruled out tilt sensors just because it allows for someone possibly carefully lifting the PC and keeping it level while doing so to dodge the trigger and avoid the security event.
The load sensors are a bit pricey and require a bit more configuration and testing to ensure they're functioning properly if more than a handful of PCs are modified in this way so while I think it would work, I would prefer to find a less expensive and simpler arrangement.
The momentary tactile switches seem the most promising, but I'm not entirely sure how much weight they can realistically support.
My question is, is there another method I am missing to ensure the PC can detect whether it is in contact with a surface at all four points that I have not considered that might be more likely to hold the weight (these are not like full ATX machines, more microATX, but it's still a good deal of weight for the actuators on the tactile switches) but not require quite so much expense and configuration?
Edit: Thanks to everyone who has offered help so far. It's been remarkably helpful already and if there's more to come so much the better. I did upvote, but it won't show because I don't have sufficient reputation yet.