EBN, Emergency Broadcast Network, was a band of media jammers from the days of the Gulf War (the one back in 1990). They disappeared from the scene a few years ago, but you can find some of their old videos over at GuerrillaNews.com.
And, as long as we’re talking about media jamming, I should throw this book at you: Jamming the Media by Gareth Branwyn.
Edit: the links here go nowhere, but a few videos are in YouTube:
…And this one in the Internet Archive.
This is as good an EBN logo as any.
…And this image has nothing to do with EBN, but it’s interesting enough anyway.