In the past, I have been very quick to contact other sellers who have copied and pasted my photos or item description or even just used my wording, word for word, but typed it in themselves. Usually, they at least claim to be unaware that this is a 'no-no' and revise their listing pretty smartly, removing any of my material.

Its a bit of a different question, if its just a title of the listing, in my opinion. Its never happened to me but I think it might be a bit difficult to make a case claiming they have appropriated your material. You can try to contact the ebayer in question and ask them to remove it but I suspect that they will deny they copied from you.