Are you sure you aren't infringing on their trademark? Ask your lawyer, and if he agrees with you, get him to write a letter to the threatening party. And real

Are you sure you aren't infringing on their trademark? Ask your lawyer, and if he agrees with you, get him to write a letter to the threatening party. And really it depends on who is doing the threatening. It's your call as to whether they are serious or not; but if you have a lawyers opinion that you are not infringing, then they are much less likely to waste their time and yours in a legal action they would likely lose.