[ithkuil]

how would you know whether NSA was listening in (for example by tapping google's links between datacenters) or not even if you successfully hack into Google's infrastructure? Not finding evidence of eavesdropping doesn't exclude that eavesdropping happened, so if that was the only purpose to hack Google, it doesn't seem worth the effort.

On the other hand if you want to read people's mail, then hacking into the provider is certainly an option.

[kbenson]

I'm not sure I necessarily buy that explanation either, but I don't know enough of the facts of this particular story to know where it falls down or is supported.

On the other hand, we don't really know what the Chinese knew, or thought they knew, about Google and how it functioned WRT government surveillance. If they had reason to believe that Google would be cooperating with authorities and would have infrastructure in place to monitor email accounts that they could look for and identify if it was monitoring the accounts they were looking for, then this explanation makes a bit more sense.