speaking personally, i would hate any firm of tracking my movements, wreaks of oppressive big brother and mistrust.
my view is you either trust me or i don't work for you - simple as ! (but then i've run myown company for 25 years

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i'm thinking along the lines if the data protection act, as used in CCTv.
btw this don't affect private dwellings,
Companies that have or manage CCTv systems which hold data, to protect people privacy from the Tv exposure type shows, the system has to be managed by a strict few nominated personnel, only they have access to the data held, and must record a valid reason for any viewing of it, maintaining a record of of who, when and why for each access incident
i think but i'm not sure, as the find my iPhone data would also contain your private journeys/appointments/mistress whatever, so would fall into the remit of this legislation.
depends if your fronty like me, i just loved to make waves when employed

, be worth mentioning to the manager, contravention of the DPA can result in a fine of up to £5k, might back them off a tad.