I think they'd do that with lower leagues where there's no real competition. At the peak though which is Grandmaster level, I can imagine them clamping down quickly. Lower leagues in a banwave but then those competing for money it's actually pretty important because I'm guessing Blizzard get a cut from the really big tournaments maybe? Seeing as you have to state all this and that and apply for a license.
Btw, this is what £900k buys you in Essex, just outside London with good transport links to the city so the prices are a bit higher than elsewhere. 5 Bedrooms (one with the curtains going down to the floor is an example of one) with 3 en suite bathrooms. The Fireplace one is in the living room which is huge. The picture of the kitchen seems to have grey on it? But you can see it in the album top right just in small form. This an example of my handiwork with an iphone camera. It's abysmal. In the upstairs landing that's my sister hiding behind that slopy thing.
http://imgur.com/a/8z8m3#cEJdDl9
Kitchen literally is huge, absolutely huge. About the size of a lot of peoples gardens, if they even have one. Goes back quite far behind where I'm standing, if you think it looks avg size in the small pic. Then a huge lounge, a utility room, a study, a bathroom, a Harry Potter cupboard under the stairs and a Garage the length of the house. Upstairs is 5 bedrooms 3 ensuites plus another bathroom. Place needs redecorating entirely >.> Some of the doors and doorhandles are hideous. Like something from the 80's.