van Eck has become synomymous with the collection of data from electromagentic emanation of computer equipment after his publication on the subject in 1985. This process if often referred to as 'van Eck Phreaking', and is also known as 'tempest' after the US governement surveilance program using these principles.

ghost of the machine next to it… http://www.newscientist.com/news/news.jsp?id=ns99992732 (or how an oscillator grew into a radio)

• Markus G. Kuhn's and Ross J. Anderson's, “Soft Tempest: Hidden Data Transmission Using Electromagnetic Emanations” http://www.cl.cam.ac.uk/~mgk25/ih98-tempest.pdf
• Wim van Eck, “Electromagnetic Radiation from Video Display Units: An Eavesdropping Risk?” http://jya.com/emr.pdf
• Christopher Seline, “Eavesdropping On the Electromagnetic Emanations of Digital Equipment: The Laws of Canada, England and the United States” http://www.eff.org/pub/Privacy/Security/tempest_legal.draft
• Ros Anderson's website is a good starting point. http://www.cl.cam.ac.uk/users/rja14/#Tempest
• Cryptome's tempest archive http://cryptome.org/cryptout.htm#NSA-TS
• The Unofficial TEMPEST Information Page. http://www.eskimo.com/~joelm/tempest.html
• Tempest for Eliza, to use your computer monitor as an AM transmitter http://www.erikyyy.de/tempest/
• All You Ever Wanted to Know About Tempest
• Declassified NSA Document Reveals the Secret History of TEMPEST > http://blog.wired.com/27bstroke6/2008/04/nsa-releases-se.html