The reason they do things like this is because experience has shown them that, when they do this to republicans, they will get away with it without punishment.

According to what I've read, Christopher Wray has some explaining to do, or expect his resignation soon.

These were not obtained legally, because it would have to be signed off on by a judge. the only other way to get it, was through the FBI.

Trump should drag in the head of NSA and fire them. Then have Barr charge him and schitt and art with a crime

I think OP underestimates the power of a Member of Congress. When a Congressman asks for information, both the government and private businesses hop to. AT&T acted like any normal, big business that was asked for information about third parties. Such is the power of the cloak of a a Congressional Investigation.

That Adam Schiff is an unethical schlub, oh, well, that is a sad happenstance. That he can sit through a hearing, orchestrate it to hide information and restrict the opposing party's rights, watch his pet theory fall apart, walk out of the room and deliver a wrap-up smear as if it all went his way, well, that is the mark of either an unethical lawyer, or one who knows he has a weak case, but is being paid to make the best of it.

Did it come from the NSA? Or was it directly from AT&T?

I think it's pretty clear that executive branch is largely in open rebellion against the constitution at this point