It is not saying that. FTA: > There are limitations this system. Potvin says certain highly sensitive code—stuff akin to the Google’s PageRank search algorith

It is not saying that. FTA: > There are limitations this system. Potvin says certain highly sensitive code—stuff akin to the Google’s PageRank search algorithm—resides in separate repositories only available to specific employees. The vast majority of code is visible to everyone, though.