It expands the definition of “electronic communication service provider”—the entities which the government can compel to assist in surveillance, such as an email service—to include any “equipment that is being or may be used to transmit or store such communications.”
“Any business that has access to ‘equipment’ on which communications are stored and transmitted would be fair game,” the organizations’ joint statement reads. “That means hotels, libraries, coffee shops, and other businesses that provide wifi could be compelled to serve as surrogate spies, structuring their systems so that they can give the government access to entire communications streams. Conscripting U.S. business into intelligence agencies’ service was a feature of the 2007 Protect America Act; Congress explicitly and appropriately rejected this feature one year later when it passed Section 702.”
I found a YouTube link in your comment. Here are links to the same video on alternative frontends that protect your privacy: