As widely reported, the Anti-Defamation League has sent a letter to cartoonist Garry Trudeau about the Doonesbury cartoon that ran May 31. They then released the content of that letter to media sources. The nature of the objection is the role of money-lenders vs. money-changers, the groups each term describes, and who Jesus confronted at the temple in Jerusalem.
I think another issue that needs to be brought up is that Reverend Sloan is clearly an ageless vampire of some sort.