This is a huge issue for me with yakkstr and I have a hard time balancing it. For starters, I don't require an email address for accounts. One of my motivations for the site is to be a place for people to talk about things without tying it to their real identity.
But I also want the site to be convenient for users to let others know about their posts, or other posts they find interesting. That's why there is the twitter, google+, and facebook buttons on each post. But these buttons pose some privacy problems.
Here's a quote from Richard Stallman, he's the author of much of the software the internet runs on. He's also the founder of the Free Software Foundation
“Facebook does massive surveillance. If there is a ‘like’ button in a page, Facebook knows who visited that page. And it can get IP address of the computer visiting the page even if the person is not a Facebook user. So you visit several pages that have ‘like’ button and Facebook knows that you visited all of those, even if it doesn’t really know who you are,” he said. source
Most people don't understand how this stuff works, so let me try to explain. When you come to yakkstr.com your computer sends a request to the yakkstr server. Yakkstr can see the address of your computer, which it needs to send you the page you requested.
So far so good. Now each of those buttons (twitter, google+, and facebook) makes a request to the servers for those companies. So the twitter button makes your computer send a request to twitter, and now twitter knows your computers address and they know which page you viewed on yakkstr. It's the same for facebook and google. If you happen to be logged into your facebook account then they also know what your facebook account is. The same is also true for the ads which come from google.
This bothers me at some level, but users also want the ease of use that comes from this sort of setup. As time grows I'm becoming more concerned about the privacy implications of these things.
I've never shared this site with anyone, wouldnt' want anyone I know coming here : / ... its miiine! But so long as they are only using the info for there own marketing surveying info and not tattling on me, im ok with it.