Today's award goes to a French "intelligence agent".
A French intelligence agent sent a text message by mistake to the mobile phone of a jihadist, inadvertently warning him that he was under surveillance and undermining an investigation, it emerged on Friday.
The target of the probe, described as an “Islamist preacher” based in the Paris area, immediately understood that his phone was being tapped and his movements monitored.
He called the agent to complain and warned his contacts that they were under surveillance. As a result, separate investigations by two different intelligence services came to nothing, M6 television reported.
“It was undoubtedly the worst mistake the agent ever made,” M6 commented. Interior ministry sources confirmed the report.
There's more at the link.
Sounds like a peculiarly unintelligent intelligence agent, if you ask me!