https://www.macrumors.com/2015/02/17/touch-id-macbooks-magic-mouse-trackpad-rumor/
Touch ID could be headed to the next-generation MacBook Air, MacBook Pro, Magic Mouse and Magic Trackpad, according to a sketchy rumor ... ...The report, citing sources, claims that the fingerprint scanner will be positioned above the trackpad on MacBooks and integrated directly into the Magic Mouse and Magic Trackpad for desktop Mac users.
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There are a few reasonable obstacles, however, that suggest this rumor may not be true. First, there is limited space above the trackpad on MacBooks for Apple to implement Touch ID, especially on the upcoming 12-inch MacBook Air. Meanwhile, integrating Touch ID on the Magic Mouse and Magic Trackpad would be complex due to the need for secure wireless transmitting authentication.
Article Link:
Sketchy Rumor Claims MacBooks, Magic Mouse and Magic Trackpad to Gain Touch ID