Response.Redirect ThreadAbortException, why it’s a good thing

A couple of months ago, I ran into a problem where I was seeing a bunch of ThreadAbortExceptions showing up in my logs. It didn’t take long to track down why – I was calling Response.Redirect from within a try/catch block in my ASP.NET code-behind page, and the catch block was catching the ThreadAbortException and writing it out to the log. But why was the ThreadAbortException being generated?