Yesterday morning everybody on the hosted service experienced their site going down, and since then sites have experienced numerous 500 errors. (Some sites have experienced this off and on for the past few weeks as well.) We are currently finishing with the checks of all databases on the hosted service, and then we will run some proactive maintenance—i.e. deleting the data from sessions, accesslog and watchdog tables that have not been automatically cleared like they should have. Don't let that stop you from reporting errors you see that you think are out of place. If you see "500 error", please send in a report with the URL of your site and we can double-check that you're on the list for the planned maintenance.