Well it’s an interesting question. From Hulu’s TOS:

a. License. Within the United States and subject to the terms and conditions in this Agreement, we grant you a limited, personal use, non-transferable, non-assignable, revocable, non-exclusive and non-sublicensable right to do the following:

Install and make non-commercial, personal use of the Services; and stream or temporarily download copyrighted materials, including but not limited to movies, television shows, other entertainment or informational programming, trailers, bonus materials, images, and artwork (collectively, the “Content”) that are available to you from the Services.

This is a license agreement and not an agreement for sale or assignment of any rights in the Content or the Services. The purchase of a license to stream or temporarily download any Content does not create an ownership interest in such Content.

While I’m not a lawyer, I’m gonna guess the lines about a revocable license are intended to cover this. Sites like Hulu rotate their content out, which I’m gonna guess means your license to view their content only extends to what’s in their library at that time. Under fair use, you might be able to argue that you can create a backup copy for your own viewing – it does say “temporarily download,” but doesn’t say you have to download it from them – but legally you’d probably be obligated to delete your copy once Hulu gets rid of it regardless.

Also, the TOS does specify that circumventing their copy protection is a TOS violation. While the DMCA grants certain exceptions to the copy-protection rule for fair use, I don’t think it requires Hulu to continue to serve you content or not revoke your license if you break their TOS. Kinda reminds me of Red Hat’s use of TOS to enforce terms that go above and beyond the GPL. They can’t exactly stop you 100%, but they can refuse to do business with you, which makes it a lot harder.