The US Government Accountability Office says that stolen sensitive military items have been purchased by undercover government officials on Craigslist and eBay. However, this is like the kettle calling the pot black. The same subcommittee determined that the Defense Department sold chemical protective suits and biological warfare laboratory equipment to the public.
While it is easy to see an element of fear mongering in this, it does remind us that private sector businesses should be checking eBay and Craigslist for their own product and counterfeits. Doing so may reveal a problem with theft, grey marketing, or counterfeiting.