Tl&dr: some Dutch traffic lights can be remote controlled via radio signals to give priority for busses and emergency services. This obviously can be hacked, as recently demonstrated by a whitehat.
The plan is gradually replace them with a more modern secure system ... which is connected to the internet.
I'd rather take my chances with local bullies over North Koreans. Anyway, paying attention fixes this :-)
https://nos.nl/artikel/2539694-verouderde-stoplichten-in-nederland-blijken-relatief-makkelijk-te-hacken