re: ELI5: Are the other intelligence agencies as corrupt as the FBI?

NSA, most likely we're the first people to go to John Solomon. It's an interesting story.

Jon said, paraphrasing, " I got home an a couple guys, obviously agents of an agency, approached me and asked if I was John Solomon. I said yes, not knowing who or what was going on. They very seriously told me that they were concerned that other agencies were spying on Trump (others) without reason.".

This is how Solomon and others got the original info regarding spygar
te/Russia collusion.

Also, the head of the NSA went to Trump tower for a meeting with Trump after security was set up. Nobody knew he was going. We still do not know what happened in that meeting, but judging from Trump's comments later, it appears this is where he was told about the spying. "Wire taps". They packed everything up and moved to his golf course over the next days. Leaving Trump Tower almost immediately.