Wow, that's crazy! It is a wild concept that certain numbers could be deemed "illegal" https://en.wikipedia.org/wiki/Illegal_number
If any data is ever illegal then by association certain numbers are also illegal.
EDIT: The Wikipedia article points this out.
8.3.4. "How will privacy and anonymity be attacked?"
[...]
like so many other "computer hacker" items, as a tool for the "Four Horsemen": drug-dealers, money-launderers, terrorists, and pedophiles.
https://en.wikipedia.org/wiki/Four_Horsemen_of_the_Infocalyp...
The legal system is not like a computer system and tech people who think they can fool it with simple tricks like it was a computer system are in for an unpleasant surprise.