Last week, in separate incidents, Gawker, McDonald’s, Twitter and Walgreens all reported security incidents. At Walgreens, hackers gained access to a list of customer e-mail addresses. The addresses were used to phish for personal data. McDonald’s said private info was exposed when a subcontractor improperly handled data. Meanwhile, over at Twitter, hackers used ill-gotten passwords from yet another breach at Gawker Media. All of the companies responded in a timely manner and let their customers know there was a breach and that extra diligence should be used.