This is ridiculous. Not intruding on someone's elixir is just common curtesy. I mean if you were lixing there first and then they came in, well you have the right of way. But otherwise, you should give way to them. Otherwise you are wasting their RL money/in-game gold (neither of which is very nice, and you wouldn't want them to do it to you) and their time.Grow up. This isn't Sesame Street. If players and guilds want to behave like children so be it, but there are consequences for such behavior. Take Taranis for example, the population has declined dramatically due to guilds believing they can "police" others. Other guilds have been created that are anti-childish behavior. Blacklisting is a two-way street. Either learn to play with others or deal with the outcome. Using an elixir is fine, but don't expect anybody else to alter their gameplay because of your decision.
*now I might not be on board for permanent blacklisting-as time passes on games some players grow up more and/or realize how things work on Celtic Heroes. So then it should be up to the clan leaders to decide.