Yes, we should require them. The WhatsApp founder didn't attempt that, he just hoped they wouldn't.

I suspect that a large class of these "business ethics" violations are actually torts, but the problem with enforcing them is that to do so you a.) need to know what your rights are b.) need to detect violations of them and c.) need to bring a lawsuit against the offender. I remember that on Google's invention disclosure form, one of the questions was "How easy would it be to detect if a competitor was using this invention in their product?", and if the answer was "We'd never know", we wouldn't patent the idea and would keep it as a trade secret instead, on the assumption that if a competitor could use the invention illegally without us knowing about it, they would, and so it was better to deny them knowledge of the invention entirely than to publish and try to enforce unenforceable rights.

When the aggrieved party is a consumer or worker, it's triply difficult, as most consumers a.) aren't aware of their rights b.) have no information about what's going on inside big corporations and c.) don't have money to sue even if they know. Many of the ethical problems in U.S. business today stem from the legal system not being able to scale up to 300M often poorly-informed citizens.

[1] https://en.wikipedia.org/wiki/Tort

In this case, Acton's not the aggrieved party. The consumer is - they could argue that Facebook's introduction of advertising and linking of user data harmed them in a way they had not agreed to when they signed up for Whatsapp, or that its purchase violated antitrust law and reduced consumer choice. But good luck enforcing that, at least in the US, where privacy protections are weak and antitrust regulators are asleep. It looks like the EU regulators actually did enforce it, and slapped FB with a $122M fine, but that's peanuts for them.

I expect/require that people not steal from me even though I don't have a contract or prior agreement with them, and I also predict that some people won't respect my property.

How does this apply to the founders though. They sold, so isn't WhatsApp now not their property?

You mean, except for criminal law? I don't see how this is in any way equivalent to adding ads to Whatsapp.

It's not against the law to lie to me in most cases, but I still have the same expectation/requirement that people will be honest with me that I do that they won't steal.

I wouldn't trust a handshake agreement on a used car.

If you feel strongly about it go further and organize more people to do the same. Try to convince people who don't feel the company is unethical that it is.

But in the end you can't expect because you don't like a company that your feelings on what should happen to come to be.

It's like so many people complaining on Twitter about Twitter not banning voices they don't like. If you don't like Twitter's policies then stop using their product. If enough people agree with you and do this they will change. If you feel it's worth spending your life organizing people to boycott Twitter then spend your life doing that. But the culture of demanding that platforms must adhere to someones arbitrary expectations as if using their platform is a right is ridiculous.

I don't know very much about Lyft but I have yet to hear anything bad about them which is pretty encouraging.

One of the Uber criticisms is that they don't respect local laws when they do such expansions, so maybe that is part of why Lyft might be more cautious. Still, non-US markets and global user bases are much more of a thing as time goes on, so it feels like they're very severely missing out.