> Don't have personal conversations on your company Slack!

You may be discussing unionization on your company Slack, though, and the employer may now use that against you. There’s a lot more than strictly work-related content, and strictly private content. A huge grey area is inbetween, and the employer shouldn’t be able to access any of them (and as the ECHR ruled, the employer may now)

If you’re worried about that, don’t use company Slack. But you should know that federal law protects employee organizing, especially for unions; if your employer retaliates, you can bring a claim against them.