Well, I hope this doesn't surprise anyone. I'm running under the assumption that people who use Foursquare and other such geolocation services are fully aware that they can be used to find out where they've been. If that assumption is false, I think I'm going to become a hermit.
But science and the acquisition of knowledge is all about pushing deeper into the implementation. We can't look at something like gravity and say, 'yep, that seems to work fine, adheres to its interface, we don't really need to know how it works, just that it passes its tests (apples fall, helium balloons float above oxygen, etc)'. We can't leave it there, because we have to know the implementation. We'll never improve if we don't. And we still haven't nailed it, but that's no excuse to stop.
It's like a beginning programmer looking at a hash table object and hitting 'view source'. What kind of programmer would he be if he didn't want to see behind the curtain at least once? How could he be expected to excel?
It's basically a full stop. Saying 'this is inconsistent, but I trust that it's fine' is basically akin to saying 'I don't want to analyse this any further'. Which, to the non-Christian, is akin to saying 'I think it might fall to pieces if I try to critically analyse it'.