There is apparently a major brute-force attack underway against WordPress sites.
I’m in the middle of teaching a week-long HTML/CSS class this week, so I haven’t had the time I’d like to look into this. But I’ve seen the news from several trusted sources now, so I feel comfortable sharing it as true.
Here are a few links for more information: http://www.siliconrepublic.com/strategy/item/32269-major-brute-force-attack/ and http://blog.sucuri.net/2013/04/mass-wordpress-brute-force-attacks-myth-or-reality.html.
Very important to make sure your passwords are secure, and to take additional steps (such as WordFence or plugins for limiting log-in attempts) to protect your sites where possible. More information to come later – stay tuned …