Loath as I am to cite Buzzfeed, but: the images of the people on the bridge are not from these protests. They are from the 2012 Istanbul Marathon. http://www.buzzfeed.com/hunterschwarz/one-of-the-most-popula...
The bridge pictures here appear to be legit. http://www.rightnow.io/breaking-news/turkey_bn_1369752659185...
Perhaps it is a popular crossing that gets filled up whenever major events are happening?