That depends on how "BYOD" the company is. There's an awful lot of companies that provide work machines that most of their employees reasonably use for some sort of personal work, be it checking their bank statements to see if they got a deposit or logging into a handful of services so their settings sync. In my opinion it is unreasonable to expect people to not do this, especially given that the alternative is quite painful with modern software. Corporate searches have a problem of not really having clear limits like a legal search might, so going through e.g. your synced web history when trying to find evidence of credential abuse (check your own audit logs!) is common.