It has been reported that workers in some Apple stores in the US have been making secret plans to form a union. The main issue is pay, with complainants feeling they deserve more in return from the world's most valuable company. Those involved in the unionization movement have been putting their iPhones to the side and communicating via Android smartphones.
https://www.notebookcheck.net/Beware-the-iPhone-Apple-workers-plan-secret-union-movement-with-help-from-Android-smartphones.601719.0.html
Or maybe use Nokia 3310s instead of smartphones if you are concerned with eavesdropping?
Best way to kill off a successful company - unionize!