Webroot has written a blog post and published a paper (as a PDF) on the lack of security with many employers who allow workers to use their own devices, including mobile phones and laptops, here.
In the 1990s, I often did production mainframe support from my own laptop or desktop at home, often through Procomm, later through a company app. For now archaic "conflict of interest" reasons I would not allow corporate property to be used in my residence. During production support, we had access to live consumer data (including military personnel), but this was at a time before security and privacy concerns were as great as they are now. It was also common and possible to take printouts home, something that probably wouldn't be allowed today.