They have no direct access to their servers. Whatever data is requested, they legally have to give. But they provide the data.
Theres taps on all the upstreams of the major US data centers. Thats their order, and Snowden made this very obvious with his leaks including their timeline of involvement. Other than those huge data centers of microsoft, google, yahoo, apple, etc, its Tier1 providers, so basically where all the ISPs in the USA get their internet to sell... From a standpoint in the USA you might as well shut off your internet if you are choosing which evil to make your request at, you aren't going to anonymously make it without going through something like TOR. From outside the USA where Tier1 providers are not tapped - duckduckgo may be a wiser choice depending on how you hit their servers. Huge however tho, .com and .net addresses are part of VeriSign which is a US company, and so, they are USA redirected, so your request traffic, IP, times etc bounces off the NSA somewhere when you visit one regardless of where in the world you are.