Facebook is once again getting pushy about how people message one another.
Two years ago, the social-media giant forced its users to adopt its Messenger app for direct communication, a change it enforced by deactivating messages in the main Facebook app and steering users to the app.
There was an uproar. Some users thought Messenger violated their privacy, while others just resented having to add yet another app.
Still, the plan worked; more than 900 million people use the app, roughly four times the number in 2014. But some continued to resist, exploiting a loophole to avoid Messenger. All they had to do was log into Facebook's mobile website using a smartphone browser like Safari or Chrome.
Now Facebook is coming after those holdouts.
In some markets, the company has already blocked mobile browser access to messages on Android phones. In others, opening messages on Facebook's mobile website gets you a warning that "your conversations are moving to Messenger" and a link to download the app.
The company will extend the ban to all markets and to iPhone users in the upcoming months, it says.
The Messenger app provides more reliable notifications about incoming messages and runs more quickly, the company says.
This might not seem like a big deal to many users but it's emblematic of a central dilemma in the modern age: We have free - as in unpaid - access to an ever-expanding array of software and services, but less and less control over how we use them.
That rankles people who have no interest in Messenger.
Michael Kampfer, a Minnesota construction contractor, says he doesn't have enough storage space on either of his Android phones to install Messenger alongside the other apps that he needs for his job.
"I have a problem with the company telling me what's the best experience is for me," Kampfer, 65, says. "I have a browser on my phone, so why should I be forced to get Messenger?"
From a business standpoint, Facebook's move makes great sense. Planting Messenger on more phones corrals a bigger audience for advertising and other moneymaking opportunities. Messenger is currently ad-free but analysts think the app could generate billions of dollars in advertising revenue within just a few years.
Facebook wants more of its users on Messenger because it can gather more personal data and introduce new features that could yield even more revenue, says eMarketer analyst Debra Aho Williamson. She expects adverts to start appearing before the end of this year.
Facebook executives say Messenger is now moving into "phase two" of its evolution, although they still aren't ready to say how the company intends to profit from it.
