Actually, the chill employer is the most dangerous.
Even if your employer is fine with personal use, courts will rule that it's all in scope during a discovery phase. I've been involved in litigation scenarios where people's personal email ended up being sifted through by the other litigant because opposing counsel convinced the judge that business was being conducted there, and there was evidence of frequent access on a corporate device.
All of your protections from a legal point of view are really defined by custody and scope of control. Data stored on your device in your home is the most protected. Data stored on your employer's PC or file server on your employer premises is the least protected.
Even if your employer is fine with personal use, courts will rule that it's all in scope during a discovery phase. I've been involved in litigation scenarios where people's personal email ended up being sifted through by the other litigant because opposing counsel convinced the judge that business was being conducted there, and there was evidence of frequent access on a corporate device.
All of your protections from a legal point of view are really defined by custody and scope of control. Data stored on your device in your home is the most protected. Data stored on your employer's PC or file server on your employer premises is the least protected.