There has to be large scale call centres. The number of calls they're making is impressive. I got two of them from different people last night (I'm in Australia).
Although that might suggest independent scammers.
It would seem inefficient to cold call the same person again if the first was unsuccessful. Although it is possible they just take random numbers from a big list and don't update it until the end of the day.
If they are indeed operated from actual call centres I would be curious to know how agents are recruited. I wonder if people actually apply for call centre jobs and are told they will be working for "Windows support" in other words, maybe some of them don't even know that they are scamming people.
