What attacks from the US have you heard of?

Does microsoft windows count?

Honestly, I imagine that other nations should be very concerned about the small number of US based companies creating all the CPUs which could easily be backdoored. Same for the blackbox wireless chipsets our phones depend on too.

That and so many of the companies that people depend on are in the US (Google, Amazon, social media, Apple, MS, etc) since you have to think that the US government is collecting massive amounts of data from those places.

Stuxnet?