Sorry to hear this, but especially true if you have something other people find real useful. That was one of the reasons I chose not to publish all my designs on Thingiverse and YouMagine. Not that this would stop someone with a few CAD skills, but it does make it a bit more difficult. The early prototypes that might need a bit of tweaking I have no issues with. Other parts that are more expensive to make for the value they actually provide are also up there. Proprietary designs and ones I have had to reverse engineer will never be up on these repositories. I get requests and sometimes even hateful messages every week about someone wanting the designs for free. I have learned to ignore the hateful ones and politely decline the other requests then move on.