USB condom
thingiverse
This compact device makes charging your phone at any USB outlet significantly safer! The small enclosure prints without support structures. Internally, it features a male and female USB connector - with only the power connected, data cables remain disconnected. Although this may limit charging to 500mA, you can rest assured that no one will tamper with your phone! Both connectors are readily available on eBay at an affordable price in packs of 10... To assemble the device, simply push the wired connectors into place (both fit from the female side) and fill the enclosure with some hot glue. Twisted version: https://www.thingiverse.com/thing:4061666
With this file you will be able to print USB condom with your 3D printer. Click on the button and save the file on your computer to work, edit or customize your design. You can also find more 3D designs for printers on USB condom.