From Trillian Won't Heed AOL's Message by Farhad Manjoo for Wired News:
But as an AOL spokeswoman pointed out, in order to use such a system, a user has to tell the software his AIM username and password, which is an inherently dangerous practice.
"That's not interoperability," AOL's Kathy McKiernan said. "This is about a company releasing software that hacks into our system, and that endangers our users."
Dude. WTF?
'Course the view that it should be like email with servers passing unauthenticated messages to each other, which is what McKiernan goes on to say, is perfectly reasonable--but afaik AOL isn't exactly pioneering in that area, and email has its own problems, like fake return addresses. And "hacking?"