Yes, saw it this morning. A few weeks ago, my son bought a coupon to have his oven cleaned and paid £20, then his neighbour mentioned the oven cleaning service that circulates their area, which charges the same all the time.
We know a photography studio that has been struggling in tis recession, and it was persuaded to offer portrait sittings on a Groupon voucher - they sold more than they could cope with, couldn't fulfil those commitments and have had to close. The people who purchased the vouchers will not get their photos done now.
Such a shame because there have been some genuinely good offers, but these scams getting on Groupon have brought down their reputation.