Do 'Clandestine Operations' really exist within CIA?
Any secret intelligence organisation is bound to have as many internal secrets as external. The easiest way to ensure secrets remain secret is to ensure as few as possible people have access to information. If information is released only on a need-to-know basis there are far fewer chances of leaks. Although we are in an age where agencies such as the CIA and MI5 are at pains to project an image of greater openness, the public are only aware of a very tiny amount of what goes on. There are always rumours flying around about the CIA being involved in any number of secret operations, assassinations and conspiracies. From CIA paramilitary groups fighting in Afghanistan to faking the moon-landings, how much of this you choose to believe is entirely up to you!

What would happen to an MI5 officer who went bad?
Disloyalty to your country is treason, and this is considered to be an extremely serious crime. So serious in fact that it still held the death sentence until as late as 1998. However in practice it has been a very long time since anyone has been punished in such a severe manner. The last person to be executed for treason in this country was William Joyce in 1946 for his support of the Germans during WWII.

Less than 10 years later the Cambridge spy ring was began to be uncovered. However none of those involved were brought to justice, and most were able to flee to Russia to begin new lives there. Even when Anthony Blunt was finally connected to the group in 1979, he was stripped of his knighthood and many of his privileges, but there was no conviction.

A traitor who received rather harsher treatment was Michael Bettaney. He had been recruited to the MI5 in 1982 as part of a drive to recruit more ordinary people as agents. He immediately proved to be utterly unsuitable for the service, but for some reason was retained. He was determined to become a double agent, although he cut such an unconvincing pose that the KGB thought MI5 were trying to set them up, and so immediately reported Bettaney's approaches. In 1983 he was sentenced to 23 years in prison, although he actually only served 14 years of his sentence.

More recently, in 2000, 87 year old Melita Norwood was revealed to have been a spy. She had spent years passing scientific and technical information on to the KGB and received their highest decoration, 'The Order of the Red Banner'. She was only uncovered when an ex-KGB officer released her files. It was decided not to prosecute her because the only real evidence of her activities came from a KGB file, and the case was unlikely to stand up in court.