EU governments rampantly spy on their own citizens and domestically held data in ways that would make US agencies blush. This is exposed over and over again but no one cares because everyone is fixated on the US.
Can your refresh my memory, of such illegal spying?
Also the GIANT difference is that US can legally spy on non US citizens, so even if I would complain that NSA hacked my company and stole a lot of people private data the Americans will just say "they did their job, all is legal" , there is need for an agreement so we respect each other citizens. if you think X is a terrorist and want to read his emails then does not matter if X is or not a US citizens you follow the laws and present a judge your evidence and ask for permission to spy.