In order to believe what you're claiming here, we have to believe that
1. There is magic css/js that can not only tell different browsers and devices apart, but can tell two phones from the same manufacturing run with the same software apart.
2. Despite the fact that this magic code would have to run in the client browser where its content, execution, and the data it sends back are all plainly visible to anyone who can hit ctrl-shift-j, no "public researcher or browser vendor" knows anything about it.
3. This technology is not used to combat ad fraud because of some weird conspiracy at Google.
It could be true, I suppose, but I don't see why anyone would believe this based on the evidence so far.
1. There is magic css/js that can not only tell different browsers and devices apart, but can tell two phones from the same manufacturing run with the same software apart.
2. Despite the fact that this magic code would have to run in the client browser where its content, execution, and the data it sends back are all plainly visible to anyone who can hit ctrl-shift-j, no "public researcher or browser vendor" knows anything about it.
3. This technology is not used to combat ad fraud because of some weird conspiracy at Google.
It could be true, I suppose, but I don't see why anyone would believe this based on the evidence so far.