Social media is a privacy concern as well, but this is clearly on another level. I don’t save my biometric data on twitter. I don’t need facebook to live a full life. And as you said, there are anonymous alternatives. There aren’t when you travel. And living without travelling at least a little bit is kind of sad. So the comparison doesn’t fit.

You can choose not to use social media… the choice is way harder for avoiding plane travel unless you can afford the time and money to use other means, which most people don’t.