This is valid point. But, IMO, I wouldn't be willing to run the risk of a confrontation while on vacation with my family by removing a towel. At some point, there's a good chance the person who placed the towel there will return and will likely be unhappy. I wouldn't want to be sitting there and waiting for that, nor would I want to leave the seat to go in the pool for fear that person would take the seat back. Even though the people who hold chairs for hours with just a towel are completely in the wrong, I don't find it worth it to take it upon myself to remove someone else's towel for myself. In a worst case scenario, I'd maybe check with a CM who's on policing duty to see if they've been watching it.