There is a new site called zeen.com. Around the same time, I purchased a few websites with zeen in the name, such as beerzeen.com, sexzeen.com, etc. Before I did that, I searched the US trademark office online and others. No trademark, yet for them listed. Also, other websites already use zeen in their domain name, and some even own zeen as a trademark. There are several water filtration companies, HP has a tablet addon called "zeen". If I purchased it before they trademarked (or before it is listed on USA.gov trademark website as of 4/17/12), can they sue me? Also, does the use of the word zeen in a few other places make it more difficult to trademark?