> Just to add EU view on "legal". This is highly illegal and it is criminal offense in same manner as wiretapping. You (as employer, even if you own employee computer) can get jailtime for this although hefty fine is more plausable.

This is not an EU-wide regulation. The UK is currently a member of the EU, and this practice is legal in the UK. Employees do not have the expectation of privacy on employer owned equipment.

(Please, lets not devolve into a conversation about Brexit, it's an unrelated tangent)