Just saw this yesterday...doesn't look like anyone has posted it here yet...
https://ca.news.yahoo.com/passport-warning-millions-heading-us-015811492.html
'Under new rules introduced by the US government, visitors travelling to America from a Visa Waiver Programme (VWP) country, including the UK, are required to have an electronic passport - one which has an embedded electronic chip.
The change came into force on April 1 but some Britons, unaware of move, have reportedly been caught out and refused entry to the US.'
As a Canadian, I'm sure I read that Canada isn't in the Visa Waiver programme. I'm sure I would have heard stories about people being stopped at the border and turned away. When we renewed a few years back, we could still get the 5 yr passport, which doesn't seem to have the chip symbol on it. I guess we'll find out next week when we head to the US if we are OK. But others in Europe and other countries may want to check their passports...looks like it isn't a huge percentage, but if you have travel plans and an older passport...