A friend of mine has repeatedly caught a colleague reading text messages on her personal mobile phone at work. His behaviour also extends to intruding into people's personal space to read phone screens over their shoulders and unlocking phones without consent to 'see what music they're listening to'. He has been confronted on several occasions for the same behaviour with other employees with no disciplinary action being taken by the employer Apparently he's using the information to report on herself and several other people in the office in an attempt to gain/secure promotion. This may be encouraged (or at least not discouraged) by the employer; his behaviour has become more blatant and more invasive over the last few weeks after the company was given notice of my friend's resignation. I think the colleague (I'm not sure about the employer or manager) may be in breach of privacy. The text messages were all sent on her personal mobile phone - she does not have a work-dedicated phone. What action would be recommended in this case?