ClassNotebook allows unlogged cyberbullying

This issue is identifed here.

https://www.yammer.com/microsofteducation/#/threads/show?threadId=767296680

by Matt Evans.

There is currently no way to disabled this feature and slightly worryingly no logs kept of the chats. Once the office online document is closed there isn't any record of the chats at all. (Potential child protection issues/cyber bullying concerns).

Please vote if you'd also like the ability to disable the chat feature. Thanks

https://sharepoint.uservoice.com/forums/329214-sites-and-collaboration/suggestions/16300306-ability-for-administrators-to-disable-office-online