Do you have evidence that the Commission has monitored private email communication? If you do, it's the stuff of mainstream media who would jump all over each other to break such a story.
"Chat rooms" needs definition, but many are what could be easily be seen as 'public spaces'. This forum for example is such a public space. Invitation-only environments are not, but would invited participation by an undercover government agent be a violation of law? I don't think so, but I'm not an attorney.
This whole topic has the potential to break new legal ground.