Complain to Flickr if you don’t think someone should be able to find you based on your email address - I don’t see an option in my account to do so. There’s an option for “everything *except* e-mail address”, but that sort of defeats the purpose of limiting a search. Your best bet would be to sign up with a different email address like jpmflickr@jpatrickm.com that pipes to your main mailbox, then if you start to get spam or anything of the sort you will know the origin and can act appropriately. Since the address doesn’t match any other address you use, you have the added bonus of public anonymization. You can act publicly and do whatever you want, but each “persona” is distinct and none are associated with any other unless you make the association yourself. As you said, you “have control over what is being shared” - you just have to control it.

To address another point, Plaxo doesn’t “[send] out a notification to everyone in my address book.” I’ve used the service for a little over a year and haven’t had a single e-mail come from Plaxo to anyone in my address book without me explicitly asking for it. Has anyone you know actually gotten a notification about your Flickr posts, or is this just a knee-jerk reaction to something you haven’t taken the time to understand?