Free is a great weasel word. When a free laptop is advertised to attract students to enrol in a training college, it is used in the right way if no strings are attached. But free is used in the wrong way if enrolling means needing to take on a HECS debt of $10,000.
Natural is a great weasel word. When baby shampoo is advertised as being natural, it is used in the right way if it contains no nasty chemicals. But if it is used for a baby shampoo which contains preservatives like phenoxyethanol, natural is used in the wrong way.
Nutritious is a great weasel word. When a fruit paste contains the same level of sugar as in a fresh fruit, it is used in the right way. But if nutritious is used to describe a concentrated fruit paste with a 2/3 content of sugar, it is used in the wrong way because it is unhealthy and contributes to obesity and tooth decay.
Fresh is a great weasel word. When bread is freshly-baked from fresh dough in a baking oven onsite, it is used in the right way. But if the bread is baked onsite from frozen par-baked dough imported from Ireland, fresh is used in the wrong way.
Lifetime guarantee is a great weasel word. When retailer promises that a product will be repaired under warranty for as long as it lasts, it is used in the right way. But if the guarantee lasts for only five years, lifetime is used in the wrong way.
Who is the judge? The Australian Competition & Consumer Commission (the ACCC). How does the ACCC judge? By deciding if the weasel word is used in a misleading way in breach of the Australian Consumer Law. What penalties does the ACCC impose? A fine and an undertaking not to use the weasel word the wrong way.