“Bots” — automated social media accounts which pose as real people — have a huge presence on platforms such as Twitter. They number in the millions; individual networks can number half a million linked accounts.

These bots can seriously distort debate, especially when they work together. They can be used to make a phrase or hashtag trend, as @DFRLab has illustrated here; they can be used to amplify or attack a message or article; they can be used to harass other users.

At the same time, many bots and botnets are relatively easy to spot by eyeball, without access to specialized software or commercial analytical tools. This article sets out a dozen of the clues, which we have found most useful in exposing fake accounts…