LinkedIn CEO Jeff Weiner voiced his opinion on Google+ on Monday, saying there just isn't enough room for the search giant's foray into social media. Weiner made his remarks at an event in San Jose, Calif., sharing the stage with AllThingsD's Kara Swisher and William Morris agent Ari Emanuel. Swisher reportedly asked the LinkedIn head honcho if there was a limit to the number of social networks that could coexist. Weiner expressed the view that Facebook, LinkedIn and Twitter had the bases covered, and that people didn't have enough free time for yet another.