People can be fooled by an “innocent text or email” on the front? Granted, the lack of sound is something, but I never assume anyone with a phone in the vicinity is innocent. I’m not even concerned about voyeurism. I keep thinking of people snapping your PINs and such.
If you are in public, always remember there is probably someone there with a camera you can’t see. A horrid way to live, I know, but necessary in this day and age.
In public you have no expectation of privacy whether your phone click or not. I think the word plague is a little harsh...