I've been on the lookout for bargains recently and I'm alarmed at the number of suspicious-looking ads.

There was a brompton deal I was interested in: the ad stated that the owner had specific reasons for selling the bike which made sense. I phoned up and was disappointed to find that the bike was already sold, but lo & behold, the seller had another. He sounded rather ill-aquainted with the spec and techincal details of the bikes, and seemed willing to meet anywhere in London. The location of the bikes acording to the listings were as vague as possible, and in retrospect the prices were too generous (yeah, guess I should have twigged earlier). I then found his other adverts on gumtree, several of them, all almost exactly the same, with the explanation of reason for sale text copied and pasted.

There appears to be a lot of this going on on Gumtree.