I don't particularly like the terms "Unprotected" and "Protected" because it implies one is fragile and the other is armored, and its not true in either one. What is a scratch but a pressure mark? Your fingernails can exert quite a bit at the tip of fingernail as we all know. Certain leathers such as pull-ups are designed to color-burst when pressure is applied and that is frequently the 'scratch' that one hears about. They can be 'pushed-out' by head and pressure from the palm of ones hands. In finished leather (Protected) there is a painted top coat. Its harder to scratch a painted surface but its doesn't mean you can't do it. Most anilines have some kind of a topcoat on them. Sometimes its a wax, other times teflon - but its always thin and doesn't interfere with the beauty of the leather. A Semi-Aniline has a heavier topcoat with pigmentation added.

As a general rule, the softer the leather, the less topcoat is on them. More topcoat + more resistance to things. In H&M, Equestrian and any of the Burnished leathers are a great choice for Anilines that can take a lot of wear and tear and still look good.