A high-profile hack of a Twitter employee’s e-mail and Google Apps accounts tops our news this week, in part because the whole saga offers a reminder about the need for strong passwords and exercising caution about what personal information is posted at social-networking sites, especially if, say, that information gives clues to your passwords. Elsewhere in security news, or perhaps we should say just about everywhere in security news, the search spread worldwide for the source of the massive denial-of-service attacks earlier this month.