Yeah... shhhhhhhhhhhh
I didn't come up with it myself but I noticed that after.
http://wiki.maemo.org/Proximus
Anyways, trademark law only applies to products that are similar. A mobile phone operator is not a similar product to a mobile phone application. Furthermore, it's unlikely they've filed for a trademark anywhere other than Belgium. If you search for that name in the US trademark database, it's registered as a type of tequila, toy helicopter, home electronics, medical apparatus, etc. all by different companies.