As the article says, agents feel empowered to find ways to deny.

Be prepared to have all your devices searched too. I'm talking about your photos, your online banking app, your emails, your Whatsapp logs, etc (just happened to an Australian I know) if they suspect you may be violating the terms of your visa. You can decline, but do you really want to cancel your trip, wait 12 hours for the next 15 hour flight back home?

(Edit: this is for non US citizens. US citizens don't need to answer any questions at entry, but be prepared to be taken aside for screening. You'll be asked to unlock your phone most likely, and if you refuse, they will confiscate it, but then you can enter.)