The ban seems to stem from "improperly obtained information about a contract [IBM] was bidding on from EPA employees." Link
IBM is down just 1% in after hours trading.
Mark Frauenfelder is the founder of Boing Boing and the editor-in-chief of MAKE and Cool Tools. Twitter: @frauenfelder. His new book is Maker Dad: Lunch Box Guitars, Antigravity Jars, and 22 Other Incredibly Cool Father-Daughter DIY Projects