GNOME has been a familiar name in software for the past 17 years, and a registered trademark since 2006. Cinnamon and MATE are both based on GNOME, and use software components from the GNOME project.
Recently Groupon announced a proprietary software product with the same name; a tablet based point of sale operating system. Groupon has refused to rename their confusingly named product despite it being a registered trademark, and has filed multiple trademark registrations of its own to take the GNOME name. Confusing all the more because Groupon depends heavily on free software for its business.
As Lucas Nussbaum puts it, Debian's Project Leader:
If you can, help raise the funds to fight back and most of all call public attention to this terrible behavior by Groupon.This legal defense is not just about protecting GNOME's trademark; it is about asserting to the corporate world that FLOSS trademarks can and will be guarded. Not just by the project in question, but by the community as a whole. As a result, all FLOSS trademarks will be strengthened at once.
Read more on the GNOME Foundation's page: https://gnome.org/groupon/