Illegality is an artificial concept.

There is no right and wrong in this world; there are only parties with enough power to enforce their will upon others. Some of those parties believe that what they do serves some public interest.

Law is an entirely artificial concept. That's the whole point of it.

Laws only work when the majority of people is on board with them, and there's a misbehaving minority against which they're enforced. It's most certainly not the case with the copyright law, at least in its current form. Or, for that matter, any other oppressive laws that aim to manipulate people through fear into doing (or not doing) something elites want.

If you're the only person that knows a particular sequence of letters or numbers you own it.

If you remove all knowledge of that information you destroy it. And by "all knowledge" I mean every known way to generate it, not just a simple representation.

There is nothing special among any single number in 160 byte string, but it contains all SMS ever sent. Some of those messages are of special interest to some people.