How sinister is this?

The boiler guy downstairs has local radio on (so I'm going to be humming various power ballads for the next few days - sorry Openspace/friends). But Foreigner aside, the radio station keeps running adverts for something called Quest For Truth, a company which offers polygraph - yes, lie detector - tests. It presents these as being 'fascinating,' but then goes on to suggest that people can use them for finding out if their partner is cheating or if someone they know has nicked stuff off them. Given the very questionable reliability of polygraphs this just sounds massively dodgy all round. As dodgy as that place in Chorlton that does extra scans of your foetus for you? Dunno. But still highly dubious.