Published every weekday, The Switchboard highlights the five tech stories you need to read.

NSA infiltrates links to Yahoo, Google data centers worldwide, Snowden documents say. The NSA is capable of breaking into the data streams connecting internal servers belonging to Google and Yahoo, the Post has learned. The intrusions took place without the companies' knowledge and likely affected Americans' personal data. "The NSA’s principal tool to exploit the data links is a project called MUSCULAR, operated jointly with the agency’s British counterpart, the Government Communications Headquarters. From undisclosed interception points, the NSA and the GCHQ are copying entire data flows across fiber-optic cables that carry information among the data centers of the Silicon Valley giants."

Yahoo won't say if it plans to encrypt data center traffic. In light of the most recent Snowden revelation, Yahoo still has not announced whether it intends to boost the security of its internal networks — unlike Google, which accelerated a year-old plan to do so earlier this summer. "This isn't a total surprise: Yahoo also dragged its feet for years before it finally announced this month it would let users log into its e-mail service on a secure connection."

Facebook to limit ads as younger teens using site less. The social networking site appears to be slipping in its most important demographic, CFO David Ebersman admitted on an earnings call yesterday. "Facebook had 1.19 billion users during the quarter," reports Bloomberg, "up from about 1.15 billion in the second quarter. The number of mobile users rose 6.7 percent from the prior period to 874 million."

The Internet of the future might not use servers. A team of researchers from the University of Cambridge have developed a new way of thinking about Internet infrastructure. In their vision, dedicated servers would cease to exist, replaced by a huge peer-to-peer network that would cover the entire Internet. Content would no longer be served from a single source, according to Gizmodo, but gathered from other users who've already loaded it themselves. "The upshot? Speed, efficiency, and reliability, with no central server to buckle under the load of demand."

T-Mobile's wacky plan to trash the wireless business model. Bloomberg Businessweek is out with a profile of T-Mobile, which has been trying to disrupt the wireless industry from the inside. "Telecommunications is not, traditionally, a T-shirt-wearing trash-talker’s business. After all, some of these companies have been around since the telegraph. But there Legere has been, for the year since the company brought him on, taunting the rest of the industry, calling out AT&T and Sprint (S) by name, and constantly repeating that T-Mobile is so unlike all of the other wireless companies that it deserves its own genus: the un-carrier."