It's easier to hide this in plain sight instead of being a secret. Take for example table top simulator, it has the ability to show where other people's cursors are so you can follow what other players are doing. If this streamed the mouse location at a high enough frequency, you now have the data needed being sent to everyone else in the same lobby. Synchronizing mouse cursors or player look vectors is a common feature and it may not be obvious that sensitive data is actually being streamed to the person doing the review.