All but one of you is dense...
... and that includes the article's author.
The suggestion here is the Scottish authorities are refusing to disclose the law. That's simply bollocks. The law was actually referenced in the article, though it seems only one commentator above may have actually read it. The law is stated in black and white, it's not hidden, secret, or anything else. What the authorities are refusing to say is how far over the threshold one needs to be before they will actually prosecute. So, taking the 30mph speed limit analogy... if you do 31mph you are breaking the law, you are an offender. But you may not be prosecuted until you do 30+x mph, and it's 'x' the authorities are declining to disclose because as they quite rightly observe that would encourage potential offenders to go above the legal threshold while remaining under the prosecution threshold. Jeez, it's not rocket science folks!
I'm on the side of the authority's decision here. As to whether I agree with the law itself is not something I'm sharing to be clear about that.