Which would be almost as impoossible to conceal as it is to escape a chastity belt you are wearing.
But if that is not enough, since this is about high-tech belts, perhaps the belt could be designed with pressure sensors that detect when someone with a body shape that roughly matches the wearer is inside the belt when it is being locked. With an electronic lock, it could even be ensured that the belt only seriously locks on the wearer's command if it detects that it is actually being worn.