> I believe shopping malls often use such signals (wifi, bluetooth) to track what your travel pattern through the mall is. They know what section of the store you spend most of your time in and what storefronts you stall at

In the EU this is forbidden unless they explicitly ask your permission. They can still gather aggregate stats but they cannot build a profile on you.

True but I wouldn't put it past them tbh. It's very easy to hide or claim a 'misconfiguration'.

Even the airports here track everyone. They say it's for public safety but I'm sure they use it for market analysis for their expensive sandwich shops too.