The week ending January 27
Topping last week's roundup of companies that had a rough week is Yahoo, which is reportedly under investigation by the US Securities and Exchange Commission about its allegedly tardy disclosure of two massive security breaches.
Also making the list last week were HP's notebook battery recall for potential overheating hazards, Verizon for the poor fourth-quarter performance of its wireless business, Qualcomm for being the target of yet more lawsuits, and Cisco Systems for a critical vulnerability in its WebEx browser extension.