This is how we watch TV in the 21st century: We fire up our laptops, our Roku boxes or our mobile devices. We open Hulu. We search for Parks and Recreation. Done.

But Hulu’s owners — Disney, News Corp. and Comcast, which respectively own ABC, Fox and NBC — are about to ruin this experience. If they have their way, you’ll need a cable subscription to watch any TV show on the Internet.

Back in the days before cable, people paid nothing to access network TV over the air. But cable programmers introduced a new model: You pay a bunch of money to subscribe to a package of channels and then you get all the TV shows you want — and many more that you don’t want.

It turns out people don’t want to pay exorbitant fees for hundreds of channels they’ll never watch (Bruce Springsteen wrote “57 Channels and Nothin’ On” even before the advent of DogTV).

Enter Hulu. The Internet TV site makes it easy for you to watch the shows you want to watch, when you want to watch them, for free. If you want to view them on your mobile device or with an Internet-connected TV, you pay a small monthly fee. That fee, along with traditional commercials, generates revenue.

Hulu now boasts 31 million subscribers who like it that way. It’s how many of us watch TV, and an innovative model for the future of online entertainment.

But Hulu’s owners are chucking all of that out the window.

The gatekeepers at Comcast, Disney and News Corp. are moving to an “authentication” system that would allow only cable subscribers to access TV shows on Hulu.

These guys are trying to put the Internet genie back in the bottle and return us to a time when they controlled television. We need to remind them that you can’t stop the future.