I ran into this the other day with a cnet download of a free-beer-ware utility for windows. It took me a couple of seconds to read through what was happening, and I barely caught it before clicking through too fast.
As for Nmap, I'm thinking a strongly worded C&D to the CNet Legal department is in order for trademark and license violations. This "your request will be reviewed on a case by case basis" is a load of bull hockey.