Just got my first empty alert. Wondering how it happened. Something
must have triggered it in the beginning, but then whatever that content
was appears to have been filtered out. So what I got looked kind of
like this:

This as-it-happens Google Alert is brought to you by Google...
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Remove this Google Alert:
http://www.google.com/alerts/remove?...******** ****

Create another Google Alert:
http://www.google.com/alerts?hl=en

Sign in to manage your alerts:
http://www.google.com/alerts/manage?hl=en