I did a search and found this link:

http://www.bayarea.com/mld/cctimes/business/6783649.htm

excerpts:
"...SBC Communications has emerged as the only major Internet service provider that has so far refused to identify computer users whom the industry suspects of copyright infringement."

and

"But SBC, the No. 2 regional phone company and a major local telecommunications service provider in the Midwest and West..."

Hope that helps.