Just clicked onto safari on my iPhone after a few hours not using it. Mumsnet was the last site I had open, I was logged in. A log in page that I had never seen before popped up, it said something about logging in to win prizes, and the mumsnet address no longer said .com (it was .io something?). I closed it and mumsnet reopened fine, I was still logged in as normal.
Is this a new thing or was it something dodgy?