With the recent proliferation of Windows 10, I've noticed a sharp increase in Microsoft Outlook & MSOffice requests that try to save the webpage and all it's associated files to the user's local machine.
I've always blocked this UA & its variants, but up until now, the profile has usually been from a person at work where MSOffice is installed. Now with Windows10, and MSOffice being one of the apps offered, the couch-potato at home can scrape our sites with ease.
The typical UA string will contain one or all of these attributes:
Microsoft Outlook
ms-office
MSOffice
As always, it is not the tool that is to blame, it is the user that misuses it.