Medscape's latest weekly Infectious Diseases email newsletter carried this 
bulletin:

FDA CRACKS DOWN ON COLLOIDAL SILVER CLAIMS
The US Food and Drug Administration has contacted a number of Internet
retailers to caution them that touting colloidal silver as a cure for
conditions ranging from sunburn to the common cold violates the agency's
regulations.
http://id.medscape.com/35682.rhtml?srcmp=id-040601