Michaels Stores Inc. says two separate eight-month-long security breaches at its stores last year may have exposed as many as 3 million customer credit and debit cards. The breach first came to light just weeks after Target Corp. said that cyber thieves planted malware on cash registers. Michaels is offering identity protection, credit monitoring and fraud assistance services through AllClear ID to affected Michaels and Aaron Brothers customers in the U.S. for 12 months at no cost to them. This incident marks the second time in three years that Michaels Stores has wrestled with a widespread compromise of its payment card systems.”]