Application whitelisting can prevent the execution of unapproved executables, that's about it. Oh, you need to run Python scripts? You're using npm? There go yo

Application whitelisting can prevent the execution of unapproved executables, that's about it. Oh, you need to run Python scripts? You're using npm? There go your whitelisting efforts... Whitelisting also won't protect you from exploits in the software itself. If some non-technical user gets compromised and starts sending out malicious PDFs, you better make sure every single installation of Acrobat is up-to-date. If you get hit by a 0-day in Outlook - good luck. Now perhaps in this case people were just sloppy, but again, if you want to rule out exfiltration of data - as opposed to just making it less likely - you need a completely different approach and it'll cost you.