I just hope it also works for pen-tablets, where the "pointer" can suddenly jump from one location to the next when the pen comes near the surface of the tablet.
Or the much more common case of touch screens. I'm assuming it's fine - the fine pointer movements are just one aspect of it, and tapping/clicking with a pen are likely to produce small movements anyway (whether or not those movements are suppressed by the driver of whatever device you're using is another matter).
That and what about those who fill their form with tab navigation ? No mouse involved here. It is just showing off ...
I just tried the one ins0 linked above, and tabbing through, using space to select the checkbox, worked fine.
Using my iPhone, it thought I was a bot.
More appropriately stated: couldn't determine a priori that you were a human.