G2G, I totally agree. If, and it's a big "if", this industry was regulated by the US govt., I could see this as a legal consumer protection issue. Here's the book's argument, "well, you see we are only in business to take peoples money, and when someone come along and wagers some money and happens to take some of ours, then we put a stop to it". It's like their motto should be, We are Not in the business of booking or taking wagers, we only want people to pour money into our accounts". No such thing as equal opportunity.
That's why I have a hard time believing ratings like SBR and TOW, who list books irrespective of their fairness to the business of taking wagers (or cutting limits) from winners.