Put the Snapchat co-founders on suicide watch: Facebook is buying WhatsApp, a smartphone messaging service that's enormously popular around the world, for $16 billion, plus $3 billion in restricted stock units for employees, making it one of the biggest tech deals in history.

It's going to be a dour afternoon for Evan Spiegel.

Over 450 million people use WhatsApp across the globe—and this will help Facebook lock in non-American users. But... Christ almighty, $19 billion is an incomprehensibly large amount of money to spend on an app. Any app.

Recent comments by WhatsApp's founders (above) also raise some eyebrows: just this past December, they claimed zero interest in selling out to a large company.

What does it take to change your mind? Luckily for Facebook, and WhatsApp's extremely well-compensated investors, something in the double digit billions must've been enough to change the execs' tune:

WhatsApp has "no plans to sell, IPO, exit, [get new] funding," Koum said.

"Despite the fact that we're able to monetize today, we're not focused on monetization," Koum said. "We view monetization as five, 10 years down the road. We're trying to build a sustainable company that's here for the next 100 years."

The company also vocally rejected online advertising:

Advertising isn't just the disruption of aesthetics, the insults to your intelligence and the interruption of your train of thought. At every company that sells ads, a significant portion of their engineering team spends their day tuning data mining, writing better code to collect all your personal data, upgrading the servers that hold all the data and making sure it's all being logged and collated and sliced and packaged and shipped out… And at the end of the day the result of it all is a slightly different advertising banner in your browser or on your mobile screen.

Remember, when advertising is involved you the user are the product.

Emphasis theirs. WhatsApp is now owned by one of the largest data-mining operations in human history.

Cash image: Shutterstock