According to [the Daily Mail][1], 

> 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?