This whole issue feels artificial and exaggerated: social profiles? seriously?! that is the least of any user's concerns. I think Twitter/Facebook and whomever should focus on their own products and not resort to these sorts of PR stunts.
They want to get to Facebook? They type "facebook" into Google and click the first link. They believe that Google is how you access the Internet, clinging onto the old AOL frontpage mentality of portals and site discovery. That's why search ranking matters so much.
Facebook/Twitter aren't the real losers here though. They will survive. The problem is that Google is pushing their results to their average content on Google+ while tossing thousands of smaller content websites aside. Don't expect that to decrease. It is too easy for them to grow profits by pushing their own content. Whether they start other content companies or buy them, this is their growth.
Example: If one company owned 90% of the media content in the world and gave it a way for free because they made money on ads does not mean they can't abuse their power. If you started your own website how would people find out about you? 90% of the search engines wouldn't show you. You couldn't advertise on 90% of magazines, websites or tv shows. And 90% of social networks wouldn't allow links going out of their site. And so on.
This is an extreme example, but free means nothing.
Who was trapped into using Windows? Why couldn't you buy another OS?
Threatening OEMs? The MS abuse I was talking about was having to do with IE only. But Google is not innocent of strong-arming companies either. If Yelp didn't allow Google to use its reviews in Google Places, Yelp would be removed from the index entirely. http://searchengineland.com/yelp-google-told-us-its-our-way-...
As for Yelp, they asked to not appear on Places and Google told them to use robots.txt if they don't want to be indexed, and the rest is spin and PR.