Via Dinah, who is cool enough to warn everyone about this:

Yahoo Opts Out Of Being Cool

Thanks to Gary at the Balboa Theatre (whose little newsletter is great) for this warning:

On March 28, Yahoo! Groups set everyone's account to the "Have your advertisers send me mail" option no matter what folks had previously elected as their preference. Because this has gone from an opt-in service to an opt-out one, if you are a member of a Yahoo! Groups-based email list (or, I assume, if you have a Yahoo! e-mail account) and have no desire to surrender your inbox to a deluge of mail from Yahoo!'s advertisers, you have to tell them that you don't want this mail within 60 days -- if you don't say anything, they will just send it.

Here's how to do it:
- Go to Yahoo Groups (http://groups.yahoo.com) and sign in.
- Go to My Groups and click on Account Info, verify your password if it asks you to, which will bring up your Yahoo ID card.
- Click on 'Edit Your Marketing Preferences' and change all those Yes's back to No's.
- Click 'Save Changes.'

It's true. I just went to my account, and everything was marked yes. I thought something had changed somewhere, since my inbox flow has tripled in the past week, most of it spam. Grrr.