Temeraire (913731) writes "Why can’t archaeologists “see” into a burial mound with a micro-seismic survey? With unlimited time and number of geophones, surely modern computers should be able to calculate high-resolution images down to a useful depth."
Oh yes there is such a thing as a free ride in London. You would be amazed what a large fraction of all bus riders are paying nothing. All old folk, school kids, and disabled travel free. When they equalized the ages between men and women for free old age bus passes, they brought men's down to 60. Very nice for me, but sometimes I feel guilty sprinting to catch the bus and then flashing an old-timer's free pass! Seriously though, the whole of transport policy in London is deeply corrupt, with hidden subsidies going in all sorts of directions, some socially desirable, but very often acting as a powerful financial engine to transfer resources from poor to rich. If this Oyster card crack serves to make a few more people aware of the problems, it can only do good.