Add these user boxes to your user page to show your support for free software campaigns and programs -- they also make it easier for other people interested in the same things to find you.
Don't be shy about creating your own, and adding it to Category:Userbox.
Usually a box reflects membership in a group, so you want a link in it to point to the group page. You can include that like:
This user is a [[member of group::Group:DefectiveByDesign|member of the Defective by Design campaign]].
The following 83 pages are in this category, out of 83 total.