Nearly every activity I've seen reported that has been leaked has been, IMHO, illegal in some way. Warrantless wiretapping, war crimes, or violations of international law. The rest have been things that are simply embarrassing, which are by statute, prohibited from being classified in the first place.
Classification has been completely misused in the second half of last century and particularly in the first two decades of this one.
Being "Illegal" isn't black and white, especially in the case of ACLU vs Clapper, which was about bulk metadata collection through FISA.
Originally dismissed by district courts, then successfully appealed as overreaching the PATRIOT act the dismissal was vacated and remanded back to district courts where it was eventually effectively dismissed during Smith v Obama when the program was sunsetted.
On the topic of war crimes, despite claims that war crimes were committed, no formal trials convicting anyone of war crimes came from either Manning's nor Snowden's revelations, despite investigations thereof [1]. This isn't just a nit-picking point, or handwaving away corruption or cover-up. If people have problems with the process, the same process that has revealed War Crimes, then that's a separate subject.
As far as I understand it, if the DOJ and the Inspector General are all on board with whatever is being done, then realistically there’s no way to get it in front of a court or the court of public opinion without risking being charged for disclosing classified material all the way up to treason.
This is where they use Third Party Doctrine which basically means "if you give information to someone else, not involved then obviously it's not private!"
Which essentially means that law enforcement can collect info from your ISP, cell carrier, grocery store, banks, and anyone else without a warrant because it doesn't qualify as a search.
It's a completely broken mindset but there has been zero effort to reform it from any political party.
Yes, that holds water if there is some point where a citizen is selecting to waive their rights to privacy. Interacting with a company as a private citizen does not change the fact one is a private citizen. Without a citizen waiving the right to privacy, such an action would constitute a violation of one's rights. There's effectively no way to "opt out" of clandestine information harvesting and that is by design. Even worse, the intelligence agencies release the tools they created quietly so that they can't get in trouble in court because they're using tools that are "publicly available" lol. give me a break. civil liberties are not being demanded by the people and will likely die as a result.
Edit: turns out we do, but it has to be actually illegal behavior as opposed to just unethical.