http://news.com.com/2100-1030_3-6156021.html
Actually, since he developed the dance in 1976, and did not file for copyright until 2004, I am curious if his copyright claim to the choreography is valid. The shift from requiring registration for copyright to not requiring registration for copyright occured in 1976 as a result of the Copyright Act of 1976. I'd need to go look at the effective date of the 1976 Copyright Act and know when the first public performance of the Electric Slide was, but Silver may be out of luck.