For the past two years the Senate Intelligence Committee has been investigating the CIA's use of torture and rendition during the war on terror. The CIA doesn't like this, because it potentially means jail-time for CIA torturers and their enablers. So they've apparently been spying on their own oversight committee in an effort to find out what they know:
The Central Intelligence Agency’s attempt to keep secret the details of a defunct detention and interrogation program has escalated a battle between the agency and members of Congress and led to an investigation by the C.I.A.’s internal watchdog into the conduct of agency employees.
The agency’s inspector general began the inquiry partly as a response to complaints from members of Congress that C.I.A. employees were improperly monitoring the work of staff members of the Senate Intelligence Committee, according to government officials with knowledge of the investigation.
[Emphasis added]
So basicly they've gone rogue then. This is not something that can be tolerated if the US wishes to remain a democracy; those responsible need to be prosecuted, and those who should have kept an eye on them sacked. Above all, the CIA needs to be purged and brought to heel and reminded of who it works for: the US government, not themselves.