No, any sharing I do HAS to REQUIRE an EXPLICIT action on my part. I have to be in full control. Visiting a web site does not mean that I believe it will be interesting to my friends NOR do I want that information shared with people on Facebook.
A like button that shares, much like the Google+ 1+ button is perfectly fine, I have to hover over it, and choose my circles to share with, and then share. It is not automatic once I visit the site.
I don't want articles automatically being linked just because I visited a page, or clicked play in Spotify, or put the toilet seat up.
It is not just privacy concerns, it is the image I try to convey while using social media sites where it is common place to be friends with your boss and or co-workers. I don't need them knowing I like the Bloodhound Gang or that I read articles about atheism in the NYT but have never read a single article about religion.
Eventually all this collected data will be used against me. What if I do a simple Google search for cancer and I end up reading an article about it, that is now shared publicly, my insurance company a few years later gets a claim for cancer they claim it was a pre-existing condition and deny me coverage.
These are all scenarios going through my head. I am all for the interconnected web, and making it easier for me to introduce my friends to new content across it, however it has to be done on my terms, it has to require explicit authorisation and must never do something automatically without my consent. If I like the content enough I am extremely likely to copy and paste the URL into my social networking sites, I don't mind that extra step. Create a bookmarklet that fills in some of the forms ahead of time for me (I have a reddit bookmarklet that fills out title, URL and the sub-reddit to post in (personal one for me to share links with friends)). I am more than happy to continue using the platform, but this frictionless sharing scares the crap out of me, and will see me closing my account sooner rather than later if it continues down the path that it looks to be going down.