The National Security Agency (NSA) penned an agreement with Israeli intelligence in 2009 that delivered American data to the foreign country, according to a new report in The Guardian by Glenn Greenwald, Laura Poitras and Ewen MacAskill. The latest revelations, based on documents leaked by former NSA employee Edward Snowden, reveal an arrangement where the U.S. hands over raw “signals intelligence” to the Israeli government—meaning that the NSA gives Israel metadata that the intelligence agency has collected.

The U.S. government memorandum of understanding with Israel published by The Guardian stresses the need for the constitutional rights of American citizens. It states that Israel cannot target U.S. persons, meaning citizens, permanent residents or anyone on American soil. But there are no legal enforcement mechanisms to make sure Israel doesn’t target U.S. persons. The NSA “regularly review[s] a sample of files transferred to [the Israeli Sigint National Unit] to validate the absence of US persons’ identities,” the document states.

Under U.S. law, the NSA cannot legally target U.S. persons, though the agency has done just that and has been castigated by federal judges for the practice. Documents released by the federal government yesterday show that a judge on the Foreign Intelligence Surveillance Court criticized the NSA for accessing thousands of Americans’ phone data.

The NSA routinely swoops up U.S. persons’ communications in the process of targeting foreign persons. The NSA makes no attempt to take out U.S. persons’ data before giving it to the Israelis. Israel is allowed to retain American data for up to a year.

Under the agreement, the Israeli intelligence unit is allowed to to “disseminate foreign intelligence information concerning US persons derived from raw Sigint by NSA” as long as U.S. persons are not identified. Israel is allowed to release US persons’ identities to its “customers”–likely other Israeli government agencies–with the specific permission of the NSA.

And in another notable aspect of The Guardian article, the strictest limit placed on the Israelis concerns the collection of data from U.S. government officials. Israel has to immediately destroy any communication they obtain that comes from a U.S. official.

While the agreement was authored in 2009, this specific intelligence-sharing relationship between Israel and America dates back to the aftermath of 9/11, according to documents referenced by The Guardian. A document states that “in the last decade, it arguably tilted heavily in favor of Israeli security concerns,” while also affirming that “the survival of the state of Israel is a paramount goal of US Middle East policy.”

It’s unclear if the U.S. shares intelligence data with countries outside of Israel and the countries that make up what are called the “Five Eyes”: the UK, Australia, New Zealand and Canada.

The U.S.-Israeli intelligence relationship is not without its snags, though. Israel spies on the U.S. routinely, and the U.S. spies right back. These tensions, though, have done nothing to impede the continuing close relationship between the two countries.

The latest Snowden revelation fills in more of the picture concerning Israeli links to U.S. intelligence. As Max Blumenthal reported in June, an Israeli intelligence firm “called Narus has provided the NSA with technology for almost a decade that enabled it to obtain and analyze at least 80 percent of communications made by Americans over online and telecom channels.”

Israel also has its own foreign intelligence collection program. As national security blogger Marcy Wheeler noted, Haaretz revealed in March 2011 that Israeli military intelligence units spy on left-wing activists abroad in an effort to combat the “delegitimization” of the state.