Crime techniques, including ones that use door peepholes, that are shown online can be easily copied. We need to be on our guard against new techniques and come up with countermeasures.

100 yen stores have been selling a simple, flip cover for the peephole for years. Problem solved. But I'm glad to see Professor Hino is caught up on the matter.

In fairness to the professor, perhaps the problem he is alluding to is more that people simply aren't even aware this type of thing is a threat, rather than there being no (obvious and easy) technical solution to it.

Personally I had no idea until reading this that people using peepholes to look into apartments was even a thing.

There was a programme on TV a few nights ago where the peephole was used by a locksmith to gain entrance to apartments where people had locked themselves out. The actual technique was a mosaic, but it was obvious what he was doing. (Right, not just peering through it. No need to spell it out here.)

Oh, and the repairs cost the poor owners around 35,000 yen a pop for the trouble.