ESO is far from the first MMO to introduce gambling boxes, and I doubt they will be the last. As it stands, I don't believe there are any regulations regarding "virtual" items. In fact, I don't even think someone can be prosecuted for "stealing" your account. Most legal systems have been slow to keep up with technological changes. Even if there was some sort of law regulating the drop rates for crown crates, I'm pretty sure the TOS clearly states that Zenimax can terminate your account and/or take away all of your virtual stuff at any time for any reason, and there is nothing you can legally do about it, regardless of how much money you spent. So it's basically "buyer beware". Don't buy any virtual item in this game (or any other game for that matter) that you're not willing to lose at a moment's notice.