I can speculate. Municipalities are small fish. Provinces are bigger fish. Quebec and Ontario are among the bigger fish in Canada. I think with Quebec enacting the first ban, it's quite conceivable that Dow decided they were going to try to draw a line in the sand and try, at best, to prevent future bans and repeal this ban, and at worst, to delay the other provinces' decisions in enacting bans through this NAFTA chapter 11 discouragement process, if you will. While there's uncertainty as to the outcome of the litigation, other provinces might be less enticed to move forward, as well as municipalities.
Right now, it would appear that Ontario is moving forward strongly. Municipalities close to home—I live in Chelsea here, one of the leaders in this issue, and they're not going to back down either. They welcome the challenge. I guess municipalities are smaller battles, so maybe they decided it wasn't worth it.