I’m pretty sure intent is part of the laws that exist. If you’re just collating information, I don’t think there’s an issue. When you’re posting that information in a forum to identify the person and send people to harass them, that’s where you usually cross a line. It isn’t the gathering of information that’s important. It’s the intent to cause harm.
Technically they have the same minimum wage. If they don’t get back up to minimum wage in tips, the employer is legally required to make up the difference. The issue is most people don’t know this, and so employers get away not doing it. This is one of the many forms of wage theft, the most common form of theft in the US.