Odds are, you’ve got more than one application or script accessing your database or SQL Server instance at any given time. You’re probably stacking them on a small number of servers in an attempt to cut down on licensing costs and resource usage. All those Powershell scripts running on the central job server are running under a single service account, and you’ve got a lazy vendor who set up both the website and back-end application server to run under the same account, maybe even on a single app/web server.
I don’t think I’ve ever had a Windows Update go bad - until this week. I recently upgraded to Office 2013 and late Monday afternoon, decided to check in with Windows Update prior to our company’s normal monthly patching to see how bad the damage would be. Nearly 1 GB of updates, thanks to my fresh Office install. But there were also a couple optional updates, including a .NET Framework update.