I think the implication is this will become trivial and trivially automated, no human investigator needed. I bet there will be plugins in one year's time to right click on a post and get a full report on who the author is.
for example, you may change the content of your comments, but if you only ever comment on the same topic, the topic itself is a signal. when you post (both day and time), frequency of posts, topics of interest, usernames (e.g. themes or patterns), and much more.