Last week served as yet another reminder of the threats posed to Americans' privacy by the post-Patriot Act surveillance state. According to the Department of Justice's annual report , FISA applications to the secretive Foreign Intelligence Surveillance Court (FISC) in 2012 revealed a continued increase in the FBI's surveillance of Americans. The report covers the Bureau's requests for electronic and physical surveillance, secret court orders under Section 215 of the Patriot Act, and National Security Letters (NSLs).

Over the last four years, the government's requests for electronic and physical surveillance have steadily increased after a brief decline in 2008 and 2009, with a total of 1,856 applications in 2012. However, the truly shocking number is how many times it applied for Section 215 orders, also known as business records requests, which as far as we know give the government extremely broad authority to access "any tangible thing," including sensitive information such as financial records, medical records, and even library records.

Last year, the government made 212 applications to the FISC under Section 215, over 94 percent of which the court found it necessary to modify – 200 to be exact. This is up from 205 in 2011 , which may not seem like a huge difference, but consider that in 2009 the FBI made only 21 requests and the FISC modified just 9.

This dramatic increase in both the number of requests and the number of FISC modifications to the requests really makes you wonder what exactly the FBI is asking for. During the debate leading up to the 2011 Patriot Act reauthorization, Sen. Wyden (D-Ore.) revealed that the government has a secret interpretation of Section 215, ominously warning that " Americans would be stunned to learn " what the government thinks the law allows.

In May 2011 we filed a Freedom of Information Act (FOIA) request to find out exactly what powers the government believes it has to obtain Americans' information under Section 215. Nearly two years later, we still don't know. The government has responded to our FOIA with hundreds of highly redacted pages of government documents, none of which reveal its secret interpretation of this law. (Oral argument on our challenge to the government's classification of its secret interpretation of Section 215 is currently scheduled for June 21.)

This year's report also states that in 2012, the FBI issued 15,229 NSLs on 6,223 Americans. This is a marginal decrease from 2011, when the FBI issued 16,511 requests on 7,201 Americans, as well as a significant decrease from 2010 , when the FBI issued 24,287 NSLs on 14,212 Americans. This decrease, however, is likely in response to an opinion by the White House Office of Legal Counsel (OLC) which limited the information the FBI could request from communications providers under NSLs to a customer's name, address, length of service, and local and long distance toll billing records. It's also important to note that this report does not disclose the total number of NSLs that the FBI issues, since the Justice Department is not required to report on requests for subscriber-only information or on NSLs that pertain to non-U.S. persons. The most recent Inspector General report suggests that the number of NSLs that the FBI issues each year is actually in the range of 40,000 to 50,000 .

Last month, a federal court ruled that the NSL statute is unconstitutional . If that ruling is upheld on appeal, the FBI will likely continue to rely even more heavily on its secret interpretation of Section 215. This makes it even more imperative that the government heed Wyden's warnings and disclose to the American people exactly what authorities it thinks it has under Section 215.