HN Reader

Reading the "Why is it bad for someone else to have your passport number?" is scary, especially since when traveling to countries like Spain and Italy, every Airbnb / Hotel requires you to send a picture of your passport. Japanese stores take your passport stamp picture for their tax-free, which contains the number on the page. Some embassies even take your passport for a few days before returning it with the visa.

Why do we treat passport numbers as passwords instead of a login?

The story is a lot more enjoyable in conference talk form than written form imo https://www.youtube.com/watch?v=lijyQ_HAysA

> Based on advice I got from two independent lawyers that was definitely not legal advice: I haven’t done a crime.

I will trust his lawyers are right _for Australia only_ (although I have my doubts, and would love to see their reasoning), but in the UK this feels like a clear breach of the Computer Misuse Act[0], and I can't recommend enough that you don't do this.

0: https://www.legislation.gov.uk/ukpga/1990/18/section/1

I believe this is the same story covered by Dark Diaries. Very interesting story. https://darknetdiaries.com/episode/84/

Previously:

Finding a former Australian prime minister’s passport number on Instagram (2020) - https://news.ycombinator.com/item?id=34966909 - Feb 2023 (41 comments)

When you browse Instagram and find Tony Abbott's passport number - https://news.ycombinator.com/item?id=24488224 - Sept 2020 (340 comments)

Despite being from 2020, this vulnerability persists in 2025 with many airlines still exposing sensitive data on boarding passes and luggage tags, making "don't post your boarding pass" still relevant security advice.

How sensitive is a passport number actually? At first glance it seems like it should be, but is it actually? I honestly don't know.

I love this blog post. Its a classic.

Love the humor. I am a fan of Alex's writing style!

That was one of the funniest/interesting blog posts I've read in a long while

What a great story teller! Well done Alex.

Really interesting, but the writing was so bad I had to bail out halfway through.

Love it

Also a security tip, mosaic like he used in the picture is not a safe way to hide sensitive data, especially the one that has movement like in the gif where he is scrolling down, the mosaic changes and gives more data to reconstruct original. The safe way is to fully black out, but be wary of not plain color almost opaque marker tools, it could look like black out but playing with contrast will still reveal the data.

Its a challenge to make things easy to use - whilst keeping them secure enough. The fact that all I need is a PNR to cancel your flight is insane

Earth revolves around the Sun? Let's see. In a twin-star system which one is going around the other? Let's make one of them have higher mass. Did the heavier one completely stop going around, or does it still wobble a bit? That wobble mean the heavier one is still going around their common center of mass. Also, since there is no static fixed point in the space, the interpretation of movement of Sun and Earth could be very subjective to the reference frame selected. There is nothing wrong if someone wants to consider Earth as that fixed point for some arbitrary local reference frame. Infact, a lot of calculations that matter to human life on Earth require that.