Beginning at about 6 p.m. Wednesday, Yahoo changed its instant messaging language to prevent third-party services, such as Trillian, from accessing its service. Like previous statements, the company said the block is meant as a pre-emptive measure against spammers from its Yahoo Messenger service.

"Spammers are being aided by entities that are abusing our systems, where they effortlessly gain knowledge of pathways and back-alley access to send spam," Yahoo spokeswoman Mary Osako said.

So, if you're on my Yahoo buddy list, I might be out.