Hound of UIster wrote:
The Sony Spectacular Spider-Man cartoon couldn't use Kingpin and according to the producers, it was because the Spider-man contract that Sony had didn't have the rights to him.
That's television rights though, and may have been covered under a different contract.
Fisk was in the CG Spidey cartoon though, so clearly Sony still had the rights to use him at that point. (Post Daredevil.)
Perhaps when the Daredevil rights reverted to Marvel, Fisk came along with them somehow? Convoluted!