As you might guess, services that absolutely demand privacy were already well-guarded, such as Gmail and Drive (both 100 percent) and Maps. Most of the improvements came from advertising, news and other services where encryption hadn't been a priority until a couple of years ago.

It's not all sunshine and roses. North America has the largest share of unencrypted traffic, and 95.5 percent of that unprotected data comes from mobile devices. Clearly, there are a lot of people running old phones (or old operating systems) that either can't support broader encryption or don't have it turned on by default. Google adds that there's only so much it can do -- some countries and organizations try to neuter encryption, whether it's for spying purposes or simply a matter of outdated policies. As quick as Google was to get to 75 percent, getting the remaining 25 percent could be much harder.