To ferret out some of the many bots on Twitter that push out political opinions, Quartz has created a bot of its own.

The new bot, @probabot_, is designed to search Twitter for accounts that are heavily focused on political topics. These accounts are fed into a tool called Botometer, which uses machine learning to determine the probability that an account is assisted by or run exclusively by a bot. Quartz has already used the tool to classify over thirty accounts, many of which have tweeted hundreds of thousands of times and have thousands of followers. One bot that Quartz’s bot identified, for example, has tweeted or has been retweeted 1.14 million times since April. Quartz has created a Twitter list for all the accounts that @probabot_ has identified as bots.

This account has a Botometer score of 65.0%, which suggests it is likely to be a bot (or bot-assisted) https://t.co/S6vQ5FI6OH

— probabot (@probabot_) October 25, 2017

The bot’s launch is timely given the ongoing investigation into Twitter’s role in Russia’s campaign to influence the 2016 presidential election. Twitter estimates that false and spam accounts represent less than 5 percent of its monthly active user base. The company said last month that its automated systems flag more than 3.2 million suspicious accounts per week, but @probabot_ shows that not even Twitter is able to spot them all.

@probabot_ is part of an ongoing effort by Quartz to use bots to both inform the site’s reporting and break news. _ransombot, an earlier project, was first to spot when the hackers behind the WannaCry ransom bot cashed out the bitcoin accounts victims had to pay into before regaining access to their machines. Both efforts were created by Keith Collins, a technology reporter at Quartz, who said that Quartz plans to use the bot’s early results to tweak its parameters and improve results in the future.

We made a bot that hunts bots. It looks for accounts that push political opinions and have high @Botometer scores -> https://t.co/7rFkGuidcq https://t.co/lde2TJOkzo

— Keith Collins (@collinskeith) October 25, 2017