Just before I give any more information please be aware I'm in WA AUSTRALIA so American advice is not useful.
So basically recently my younger sister (18) shared a link to the SDA (union) website to a casual snapchat group with other coworkers at her McDonalds. She shared it to let the other workers know where they could get more information about their working rights in case they were curious. The reason the topic was brought up is because they were not given payslips for that week, although this issue was later fixed.
She also shared a link to the SDA on her personal Instagram story to talk more generally to her peers about making sure they are aware of their working rights.
Fast forward to today, she goes in to work and one of the other workers has screenshotted both the snapchat message and the instagram story and sent it to the manager. The store manager then took my sister into the office and literally yelled at her for doing this. She said since my sister is not a parent, guardian, manager or official union representative that she should not be sharing this information because it “disparages the store” and makes workers “look for things to complain about.”
This is obviously not a thing as far as I'm aware, so what can we do to get back at them and make it clear that this is really fucked up? Is this actually illegal to use a worker's personal information against them, and could this constitute a threat in any way? My sister says she felt like she was being threatened and like her manager was being aggressive. Appreciate any contributions you might have!