Disable Notification on the Lock Screen in Mavericks:
As much as Apple wants to push this as a “Feature”, I strongly feel like this is a huge security and privacy risk. Anything that can push any data past the lock screen is a little on the scary side for me. Especially if your iMessage notification are popping on your lock screen while your at lunch and you have friends like mine, or someone sends you a confidential message and it in-convieniently displays the subject and a small snippet of the message body text. So this is how to turn it off.