If you get paywall, use incognito.

I agree, it's a big problem - if someone steals your phone, they have access to your authentication for your various accounts. I minimize what things are linked to my phone number, but even so, many accounts require you to have a phone number that they WILL use to send authentication texts etc. I'd love to see a solution like the one they proposed in the article.

They don't have to steal your phone, they just have to get your phone number. So many stupid apps and whatever store the number, then get hacked. Think about Pannera Bread, which had a breach a year ago. Most of the data was just names and phone numbers, which seems benign on the surface, but you can do a lot with that info.