In a show broadcast on BBC One, the child waltzed past all the hi-tech security in one of the most heavily guarded buildings in the country to install a keylogging device onto a computer terminal belonging to MP Anne Milton.
Milton agreed to leave her PC in the hands of the BBC's Inside Out programme for just one minute. The production team had lined up six-year-old Brianagh from Winchester to see what damage she could do in that time.
Once the kid had waddled past heavily armed guards and through x-ray machines without a hitch, it took her only 15 seconds to install a £50 keylogger onto the PC.
The small girl, who apparently has very little knowledge of computers, was still able to install the simple keylogging device onto the computer in just a few seconds.
Keyloggers plug in between a keyboard and a computer. Once installed they log all of the keystrokes made on that keyboard. This information can include usernames and passwords on sensitive accounts, credit card information, private emails and other messages, personal diaries.
Equally worrying is the fact that it would take someone just a couple of seconds to remove the device without the computer owner having any idea that it was ever there. Then the information could be downloaded onto another computer and a quick sift would reveal the sensitive information.
"It really surprises me," said the Conservative MP for Guildford. "It's the speed, the size of the device and the ease with which it was attached to my computer. It's frightening to discover."
When contacted, the House of Commons declined to comment.