> this type of hacking is entirely legal under DMCA, that's actually quite clear.

Woah! I had no idea. Is that also true in the US? Do you have some sort of authoritative source?

Yes I mean the US, the DMCA is a US law. You can google it but "The specific legal source that allows you to hack or jailbreak your own smart TV is the U.S. Copyright Office's Triennial Section 1201 Exemptions."