Certainly they should share - but must stretches things a little far. Much in the same way as Amazon should provide their low-tech workers with livable conditi

Certainly they should share - but must stretches things a little far. Much in the same way as Amazon should provide their low-tech workers with livable conditions - but unless the law and applicable contracts specify otherwise, there's no must about it. Cloud providers are doing an end run around the intention of the GPL - but not around its legal constraints. (And before we consider possibilities otherwise, it might be more pertinent to at least attempt to punish companies in blatant violation - like the multitude of router manufactures routinely shipping GPL derived software without reasonable access to source.)