thekraut, that's not true. Here in Heidelberg, there is an Absinthe shop, with the "world's biggest selection of Absinthe". And I reckon they're right; it's full of the green liquid in every single format from around the world - all available to buy. Alcohol percentages range from about 25% to over 80%.
It is true, though, that a lot of absinthe bought in pubs etc. (even in Britain) only has the unique flavouring, rather than the actual hallucinogenic substance found it the "real" varieties.