Buying a coffee is not a private activity.
But it's not a celebrity activity either. It's normal daily life which is what I see the bill designed to protect. If you or I were buing a cup of coffee, would there be dozens of Paps taking pictures and selling them? I think not.
I think it's about a celeb not being fair game anytime they're outside of their own house. I think it seeks to restrict Paps to shooting only when a celeb is "On" or 'at work'.
When you're getting coffee on the way to work in the morning, are you getting paid by your employer?