[flakeoil]

You don't need very detailed imagery to spot a swimming pool. The Google earth type images are enough.

It can also be used to spot building extensions etc. And it also gives a hint on other cheating and crime, for example if the household is on benefits, pays no tax and all of a sudden a pool pops up in the garden. It might still be legit, but at least an investigation can be done.

Sure it might be seen a bit over the top, but what are the alternatives? If people do not declare when it is taxable, then things might need to be enforced. Sure these taxes could be removed, but at the same time it might be fair to tax people who can afford building a pool. Probably better than increasing tax on work.