The American Civil Liberties Union's lawsuit against the NSA is gaining steam — and the support is coming from some interesting quarters. High-profile conservatives have begun filing amicus briefs on behalf of the ACLU. Among them is the National Rifle Association, which argues that the NSA's surveillance activity could allow the government to identify gun owners and potentially circumvent the Second Amendment:

Each of these programs standing on its own could provide the government with an extraordinary amount of information about those who communicate with the NRA for any reason. Under the programs revealed so far, the government may already possess information about everyone who has called the NRA by phone, e-mailed the NRA or visited the NRA’s website. Conversely, the same programs would also gather information on potential members or donors contacted by phone or e-mail for NRA membership recruitment or fundraising programs, or for legislative or political reasons such as the transmission of legislative alerts or get-out-the-vote messages. The programs could also reveal at least the outlines of research and advocacy activities undertaken by NRA staff. ... Any of these forms of tracking could easily reduce individuals’ desire to interact with the NRA.

The NRA isn't the only right-leaning amicus in ACLU v. Clapper. Rep. Jim Sensenbrenner (R-Wis.), author of the Patriot Act, who previously said he never meant the NSA to go as far as it did, has also filed a brief. Sensenbrenner accuses the Obama administration of assuming Congress was okay with the surveillance, simply because it didn't object. But much of Congress never had an opportunity to debate the program, Sensenbrenner argues:

Defendants’ only evidence supporting implied ratification is the assertion that a 5-page report was made available for Members of Congress to read in a secure location for a limited period of time in both 2009 and 2011, when Congress was considering whether to reauthorize Section 215 as a whole. ... However, the 5-page report was only a brief summary, sorely lacking in detail, with only one sentence that hinted at the breadth of the program. Moreover, the report was not made available to House Members in 2011. ... Nor were Members of Congress given access to any of the FISC orders approving of the bulk collection of call data. Even if mere notice were enough, it would have to be actual notice. Defendants make no attempt to demonstrate that all, or even most, Members of Congress had actual notice that the government was engaging in the bulk acquisition of the telephone records of Americans.

The two briefs join a third, filed last week, by two former members of the famous Church Committee that investigated the government's use of intelligence assets against U.S. citizens in the 1970s.

It shouldn't come as a surprise by now that privacy is a bipartisan affair. "The government's dragnet surveillance practices are offensive to Americans from across the political spectrum," wrote the ACLU's Noa Yachot in a blog post.

Earlier this summer, a vote to defund the NSA was narrowly defeated in the House. It produced a cross-cutting tally that saw Democrats and Republicans crossing the aisle in both directions.