Collecting email addresses is a valid part of growing a nonprofit list. "Michael L." (whose profile I can't find) posted to Care2's Frogloop blog with a complaint that political campaigns are beginning "what might be a growing trend of adding email address to a mailing list without allowing the user to choose whether to opt-in or opt-out of the list." He explains that if one signs a petition on many web sites, one is automatically added to the candidate's email list.

He goes on to quote the DMA's Ethics guidelines saying "you should provide choices of opting out online." (Note that I can't find that quote in the link he provides, but maybe it's somewhere in the DMA's site).

We don't think this is a deceptive practice at all. We think it's normal, standard, and acceptable. If nonprofits practice CAN-SPAM compliance, then in the very first email a petition signer gets, there will be an opt-out or unsubscribe option. (For more on CAN-SPAM see our article.)

We've even talked to nonprofits (including some in the NonProfit Times Top 100) that don't add online donors to their email lists because their donation page didn't have a specific opt-in checkbox. Ridiculous, we say. A donor wants to know what you're doing with her money. She can opt out when she gets the thank-you email, or at any time after that.

So go ahead and test all of the email capture techniques you can. And yes, of course, honor the right of the subscriber to opt out in every email.

Rick...