But where is the line exactly?

This is what courts are for. There is no exact line because many situations are different.

Surely you don't have to have a big red cancel button on every page of your platform

Why not?

Some examples would be helpful

The text you quoted is clear enough to me, and it's probably clear to any reasonable person (most rules are written this way). If you're worried about gaming the system to find the exact process that just on the "legal" side of things, you probably aren't reasonable.

Ya, a reasonable interpretation would likely mean that where you sign in and manage your accounts and payments you have the means to discontinue further service. Anyone trying to push these boundaries will likley find themselves on the wrong side of the law.

> This is what courts are for. There is no exact line because many situations are different.

So now you’ve opened a bunch of businesses up to liability from an upset customer who files a complaint, even if they are making a good faith effort to follow this law.

That is why clear and specific details should be in the law, not vague hand wavy things that require lawyers and judges to interpret.