I was a customer facing employee for a company whose underhanded policies caused me to face a lot of (legitimate) hostility. I eventually quit for this reason, and I know at least one other employee who did. That company lost two otherwise good employees. It works, it's just a question of how much collateral damage you're ok with. If management want to use front facing employees to shelter them from customer grievance, what other target to people have?
Did things change after you left?
Yes. But...
It is a bit off to attack the drones of a corporate, albethey the only available target?
Do you really need that burger? Better to boycot them entirety
(Easy for me to say, I dispise MacDonalds food)
The particular problem here is there's no feedback as to why you boycott them.
You see, the following headline has more effect on CEO's and decision makers
"McD's sales drop 10% after customers refuse the app and other forms of spying" --Forbes
If it's a silent boycott then you see stupid headlines like
"Are millennials killing McD?"
Remember the entire purpose isn't so that one company doesn't track you with an app, is so every company figures out tracking you with an app is a bad idea.
So write to the news. The problem is not lack of publicity avenue, it's too few people seem to care enough about apps selling their data to make the headlines in the first place. They'd rather just get the burger and not care.