The blog you were looking for was not found. If you are the owner of this blog, please sign in.Upon signing in, they see their dashboard, and no mention of the missing blogs. Possibly they see the advice
You are not an author on any blogs yet, create one now to start posting!
In other cases, a blog owner may sign in, and see another previously experienced frustration
Blog is not locked
Your blog is not locked and does not need a review. If you are having problems accessing your blog or if you received an email saying that it was locked, please leave a message in the Help Group and we will investigate the issue.
After a brief diagnostic session, Blogger has issued a terse advice
We've identified a bug this morning which may temporarily delay the spam restoration process. If your blog or account was marked as spam recently, you may experience this delay.
The expectation is that your problem may be automatically resolved by them, though this may take a few hours.
If you are seeing this display in place of your blog, and clicking on "sign in" leaves you with no opportunity to request review of your blog - or if "sign in" cannot be clicked - first check security settings on your computer. Proper function of this display may require, as with Comments, Stats, and Template Designer, attention to cookie and script filtering.
If you are certain that cookie and script filtering, on your computer, is not an issue, post in the rollup discussion, in Blogger Help Forum: Something Is Broken. Please read instructions, before posting there.
(Update 2010/12/15): Blogger Support states that the problem which caused the locking of the blogs was corrected, all blogs affected were restored, and all side effects were corrected. The rollup discussion was closed also.