Yep, 5o USC 1800, et seq, and in my opinion, the 1804/1805 warrant was sought to obtain 1809(b) insurance policy, immunity from criminal prosecution for warrantless snooping. In other words, snooping didn't start with the warrant, and the point of the warrant wasn't to "authorize snooping." The FBI and other agencies snoop when they feel like it, for any purpose, and the law is a toothless hag.
Sundance did a very good job of laying out speculation on the relationship between the blanket warrantless surveillance described in 702 surveillance, 5o USC 1881, et seq, and the specific court orders directed against Carter Page - the subject of the dueling HPSCI memos. Read Tying All The Loose Threads Together - DOJ, FBI, DoS, White House: "Operation Latitude".
"Unmasking" of the names or ID or US persons can happen in the context of both searching the foreign communications database that is obtained without a warrant (702), and the communications obtained under a Title I court order. Both protocols include "minimization" procedures, which is essentially "masking" procedures.
What Admiral Rogers found unjustified unmasking (violation of agreed minimization) in the 702 database. Whatever minimization tightening followed from his detection would not transfer to a Title I search program.
The country has been down this road before. Somehow the fact of wholesale government snooping on the public becomes a point of discussion. Some outrage is ginned up to comfort the public, hearings are held (for example, the 1973 Church Committee), laws are passed that are promised to "fix this so it never happens again," and the ultimate effect of the law is to legalize an expansion of the wholesale snooping on the public. The FISA law didn't rein in snooping, it expanded it, and even created a "star chamber secret court" to make it appear the snooping had third party oversight to protect privacy interests. We have no more privacy against our government than the North Koreans have against theirs. Same, same. We just waste more money on a facade that calls itself "privacy protection."
I would hope - perhaps to no end - that involved folks will be totally bankrupted and perhaps go to jail (this is wishful thinking) for these actions.
On of the Go Deep Links is to Mike is Out Michael P Kortan Quits FBI
This contains an interesting piece of information citing Strzok's tweet:
As pointed out, the referenced gang of coconspirators against the Constitution included:
Given all of the speculation about Priestap [head of counterintellignece] having been turned and singing, I have advanced the alternative theory. Head of CI at the FBI is an awfully sensitive position to leave someone who is has engaged in conspiracy against the government, and it is my alternative theory that Pirestap was never part of the conspiracy in the first place. How can that be? Well CI ops are all compartmented and there is no law that the head of CI has to be read into any particular operation - for instance one initiated by the head of the agency (Comey at that time).