It is, but Kyle's "protest" is making absolutely no difference.

What protest? If the site is illegal in the UK, he has three options:

1) add age verification to comply

2) cease operating in the UK by blocking traffic

3) operate in violation of the law, making travel to anywhere the UK has jurisdiction dangerous

I don't think he's intending on changing UK society by blocking their traffic because, as you point out, that's not a good way to effect change.