We have a website featuring Sitecore 8.1 with multiple content editors. Is there any way to log their activity, as in listing the actions they have performed in terms of editing/publishing/unpublishing?
We had a problem last week which I suspect being caused by someone unpublishing the wrong item, but I need to make sure this is the case, or at least I would like this ability in the future. Do I need to create my own event-triggered logging?
There's nothing fully out of the box to provide those reports in Sitecore. You can take a look at the Sitecore Audit Trail module which will log all the "editor action" audit information into a separate log4net appender. You can find more information on the module in this blog post, but note that the module is only mark as compatible to Sitecore 7.5, it should not be hard to make this work with Sitecore 8.1, namely updating the appender config since the log4net config is now within the <sitecore> node in config.