"During scheduled maintenance work Wednesday night, we experienced some data corruption that impacted Blogger’s behavior," the company says on the Blogger blog. "Since then, bloggers and readers may have experienced a variety of anomalies including intermittent outages, disappearing posts, and arriving at unintended blogs or error pages."
A small subset of Blogger users (Google estimates 0.16 percent) may have encountered additional problems specific to their accounts.
All day April 12, 2011, Google put Blogger in read-only mode while restoring content. As part of the repair process, Blogger rolled back to a Wednesday May 11th version, leading to deletion of material on a temporarily basis.
In the afternoon of April 13, Twitter is reporting service disruptions as well.