I presume you wouldn't say it was "wrong" of the United States to crack the German and Japanese codes in WWII...
...so when US adversaries (and lets just caveat this by saying people YOU, personally, agree are legitimate US adversaries) don't use their own "codes", but instead share the same systems, networks, services, devices, cloud providers, operating systems, encryption schemes, and so on, that Americans and much of the rest of the world uses, would you suggest that they should be off limits?
This isn't so much a law enforcement question as a question of how to do SIGINT in the modern digital world, but given the above, and given that intelligence requires secrecy in order to be effective, how would you suggest the United States go after legitimate targets? Or should we not be able to, because that power "might" be able to be abused -- as can any/all government powers, by definition?
This simplistic view that the only purpose of the government in a free and democratic society must be to somehow subjugate, spy on, and violate the rights of its citizens is insane, while actual totalitarian and non-free states, to say nothing of myriad terrorist and other groups, press their advantage. And why wouldn't they? The US and its ever-imperfect system of law is not the great villain in the world.
Take a step back and get some perspective. And this is not a rhetorical question: if someone can tell me their solution for how we should be able to target technologies that are fundamentally shared with innocent Americans and foreigners everywhere while still keeping such sources, methods, capabilities, and techniques secret, I'm all ears. And if you believe the second a technology is shared it should become magically off-limits because power might be abused, you are insane -- or, more to the point, you believe you have some moral high ground which, ironically, would actually result in severe disadvantages for the system of free society you would claim to support.