Alternate title: "Help me Obiwan Ponoko, you're my only hope"
I'm a 3D designer making models designed for 3D printing. Home 3D printing mostly. I have a ton of designs on Thingiverse (132 to date) but as my skills have improved I wanted to transition to a paid marketplace. This is still in the very early days and there are very few places that are basically Thingiverse but with a paid option. However in my searching I ran across a few places that, in order to keep their designer's "safe" don't sell the 3D model and instead sell a stream of pre-sliced data that you have to pipe straight to your printer. I scratched my head at that and wondered for a bit before I realized that I've seen this sort of thing before. It's copy protection of the worst kind. These days we call it "Digitial Rights Management" or DRM, but it's basically the same sort of copy protection nonsense that we've seen fail for 30 years of digital media. I did some soul searching and decided that DRM is wrong, that it causes more problems than it solves, and I would not support it.
Eventually I found 3 store fronts where I could sell my digital files and my customers would get the actual 3D files they can use to do home 3D printing. Then today one of them sent me an e-mail announcing that they're changing to a streaming model. So I contacted the other one and found out that they're doing something similar, in that you don't buy the 3D model from them, you buy the model and they'll print it for you. So now there's only one and it's you.
I know designers are afraid of their models being copied and they are begging in fear that their designs be somehow protected from the very people they're trying to sell to. It's silly. I prefer to trust my customers to do the right thing and give them the tools they need to make my designs. If they want to print it out at home or here or find someone online to print for them they should have that ability.
Please just keep doing what you're doing. If designers are bugging you to protect their models do not give in to them. Maybe Ponoko doesn't care because you're more digging on your manufacturing, and that's okay. But please just keep doing what you're doing.