Facebook has revealed over one-third of its 70-strong security team is employed to handle requests for data from law enforcement agencies.
Speaking to Forbes Magazine, the social network's chief security officer Joe Sullivan said Facebook received "thousands" of calls and emails each week from agencies seeking user information.
Sullivan said that "basic subscriber information" like usernames, email and IP addresses is handed to authorities if they have a subpoena.
Gaining access to further details required a warrant, Sullivan said, although in "life-or-death emergency" cases - such as a child abduction - such legal requirements could be waived.
Sullivan told Forbes that the US Government tended to back down from - rather than fight - requests that are denied by Facebook.
At least one government agency had also attempted to have Facebook log data outside of what the site already collects, Sullivan said.
Facebook knocked back the request on advice from "general counsel", he said.