Mixed reactions are starting to emerge from a Reuters report that the U.S. government wants to let spy agencies get widespread access to massive amounts of data on Americans and other people who use U.S. banks.

Details were included in a Treasury Department document, and the plan would allow spies and others to locate terrorist networks and crime syndicates – a goal of many in law enforcement and federal intelligence.

Privacy advocates would likely oppose the plan, but sources told Reuters it is legal under U.S. law. So far, it is only a proposal and could be scrapped based on U.S. reaction.

The database is related to the requirement that banks and other financial institutions report large transfers of money, or “unusually structured bank accounts” to the Treasury Department's Financial Crimes Enforcement Network (FinCEN), Reuters said.

The FinCEN database would be linked to a computer network used by U.S. defense and law enforcement agencies called the Joint Worldwide Intelligence Communications System. There are over 15 million "suspicious activity reports" sent to the Treasury Department a year.

"For these reports to be of value in detecting money laundering, they must be accessible to law enforcement, counter-terrorism agencies, financial regulators, and the intelligence community," said the Treasury Department document, reported by Reuters.

The FBI has access to the database now. Spy agencies, like the CIA and the NSA, request access on a case-by-case basis.

But when told of the proposal, Sharon Bradford Franklin, senior counsel for the Rule of Law Program at the Constitution Project, said the plan "raises concerns as to whether people could find their information in a file as a potential terrorist suspect without having the appropriate predicate for that and find themselves potentially falsely accused."

Michael German, senior policy counsel for the American Civil Liberties Union, said a similar proposal was previously withdrawn. He noted there is “wiggle room” on “how the information will be used,” Reuters said. “Time and again, we have evidence, unfortunately well after the fact, that somebody's civil rights have been violated, that the intelligence community simply ignores the rules,” said German.

“Under the similar umbrella of preventing terrorist activities, this proposal comes in the wake of the drone controversy, and might spark more anger regarding civil liberties on both sides of the political aisle,” according to another report from Policy Mic. “On the one hand, this gives the spy agencies more ammunition in the War on Terror, and could help thwart domestic attacks. However, any move by the government to track its citizens more than it already does is going to be seen as an encroachment of privacy and rights.”

In addition, the plan comes as other rumored government efforts are creating anxiety. TechZone360 said it was recently reported by Wired reporter James Bamford that the NSA intends to “intercept, decipher, analyze and store vast amounts of the world’s communications from satellites and underground and undersea cables of international, foreign and domestic networks.”

These include “private e-mails, mobile phone calls and Google searches, as well as personal data trails – travel itineraries, purchases and other digital ‘pocket litter” in a Bluffdale, Utah data center.