This may have been mentioned elsewhere on these forums, but I can't find it. I received an email this morning purporting to be from Adobe with a "user key" attached as a zip file:
Your Adobe CS4 License key is in attached document below.
We encourage you to explore its new and enhanced capabilities with these helpful tips, tutorials, and eSeminars.
Thank you for buying Adobe InDesign CS4 software.
Adobe Systems Incorporated
Something else to watch out for. But you'd think at least they'd refer to the current version of the software.