I am seriously annoyed at people who create documents for a group to use, and then share them through a collaborative feature in, say, MS Word, instead of saving them in the shared folder that is supposed to be used for this. That means a) of you miss someone in the list of people with whom the document is shared, they cannot access the relevant information contained in it; b) when I want to find an older such document I have to search through my emails to find it, instead of just looking in the relevant folder; c) it is so easy that someone accidentally saves a copy, leading to several versions of the same document.

My colleagues know well that I'll say "put it on Sharepoint!" every so often.