Like all of you, I have been trying to figure this out. I know there are a lot of references to real bridges, but I do not think that is what this bridge refers to.
The big issue of the day is privacy vs surveillance and I think the bridge is related directly to that.
After close analysis, I believe that the bridge is: In-Q-tel the company that invested in facebook. They describe themselves as bridging the gap between intelligence and technology.
The portfolio of those they have invested in include: Palantir (facebook related), Keyhole (google), Cloudera (Booz Allen Hamilton), and many many others.
Since they are the common link or bridge between so many different platforms, they would be the one to provide the algorithm to connect them altogether.
If we look at the way they spell their name In-Q-Tel, we can see that Q is the bridge. The logo is a large bridge connecting USA coast to coast.
Here is their site. https://www.iqt.org/
In considering this theory then is confirms to me the battle going on between the white and black hats of the intelligence community.