Former National Security Agency contractor Harold Martin allegedly stole documents that seem far more sensitive than what has come from the Snowden leaks.

For more than two decades, Martin allegedly made off with highly-classified documents that were found in his home and car that included discussions of the US military's capabilities and gaps in cyberspace, specific targets, and "extremely sensitive" operations against terror groups, according to an indictment released Wednesday.

Martin was arrested by the FBI at his home on August 27, 2016. Agents found thousands of pages and "many terabytes of information" there, according to court documents reviewed by The New York Times.

With the release of the indictment, it has become more clear of what was apparently in those files.

The indictment charges Martin with 20 counts of having unauthorized possession of documents from not only the NSA, but also from US Cyber Command, the National Reconnaissance Office, and the Central Intelligence Agency. While many of the documents leaked by former NSA contractor Edward Snowden were top-secret, they mostly consisted of PowerPoint presentations and training materials.

Top-secret documents allegedly stolen by Martin, however, offer much more specific and damaging details to potential adversaries. Here's a sampling (via the indictment):

A 2014 NSA report outlining intelligence information regarding foreign cyber issues, containing foreign cyber intrusion techniques

A 2009 draft of a United States Signals Intelligence Directive, which outlined specific methods, capabilities, techniques, processes, and procedures associated with [computer network operations] used to defend the United States.

An NSA anti-terrorism operational document concerning extremely sensitive US planning and operations regarding global terrorists.

With just those three documents, an adversary would have details on how the NSA stops hackers from penetrating its networks and what kind of gaps still exist, along with how the agency plans operations against terror groups. Though it's not apparent from the indictment that Martin passed the documents along to anyone, if he did so it would be a huge setback to the intelligence community.

Soon after Martin's arrest, his lawyers told The New York Times that he "loves his family and his country. There is no evidence that he intended to betray his country.” A US official described him as a "hoarder."

The indictment continues (emphasis added):

An outline of a classified exercise involving real-world NSA and US military resources to demonstrate existing cyber intelligence and operational capabilities .

. A description of the technical architecture of an NSA communications system.

of an NSA communications system. A USCYBERCOM document, dated August 17, 2016, discussing capabilities and gaps in capabilities of the US military and details of specific operations.

in capabilities of the A USCYBERCOM document, dated May 23, 2016, containing information about the capabilities and targets of the US military.

A 2008 CIA document containing information relating to foreign intelligence collection sources and methods, and relating to a foreign intelligence collection target.

For at least a portion of Martin's career, he served in the NSA's Tailored Access Operations unit, an elite group of government hackers tasked with breaking into foreign networks. Some US officials told The Washington Post that Martin allegedly took more than 75% of TAO's library of hacking tools, a potentially massive breach of an outfit that has been shrouded in secrecy.

According to The New York Times, some investigators suspect Martin may possibly be the source of the trove of TAO hacking tools that were posted online last year by a group calling itself "The Shadow Brokers." Those disclosures likely spurred "a lot of panic" inside the agency, according to a former TAO operator who spoke with Business Insider last year.

“The FBI investigation and this indictment reveal a broken trust from a security clearance holder,” Special Agent in Charge Gordon B. Johnson of the FBI’s Baltimore Division said in a statement.

“Willfully retaining highly classified national defense information in a vulnerable setting is a violation of the security policy and the law, which weakens our national security and cannot be tolerated. The FBI is vigilant against such abuses of trust, and will vigorously investigate cases whenever classified information is not maintained in accordance with the law.”

Martin faces a maximum sentence of 200 years in prison. His initial court appearance is scheduled for February 14.