2 of 3 The claim is about Sports Direct, not JD Sports (these are different companies)

Are Sport Direct 'using fingerprint recognition to ID unhappy workers'?

According to the Daily Mail,

Sports Direct bosses asked warehouse staff to press 'happy' or 'sad' emoji buttons to say how they felt about their working conditions - before using fingerprint recognition to ID unhappy workers, according to a trade union.

Is this really being done?

Can it be done? I imagine that it would require a camera behind the emjois, to capture images of fingers which press them. Even so, how would they link those to employees?