This has health privacy implications far beyond just the affected patients...
I read the story and wondered why the RFL had done a deal with Google rather than British researchers who, presumably, would be able to analyse the data perfectly well? A moment's thought and the answer becomes perfectly clear: the reason Google were chosen is because they fully intend to identify the individual patients and match them with the 'lifestyle' (aka browsing and online purchasing history) that they have for these people.
So welcome to the future: where Google and its advertisers know you're ill before you do. The next time you come to insure your car and find that you can't get a quote for anything less than a thousand times the value of the car, make a note to go and see your doctor. :-(