Elon Musk and his legal team have attempted to use advertising technology to strengthen their defence against the lawsuit from Twitter Inc (NYSE:TWTR) as the legal battle rumbles on the billionaire's aborted takeover.
In his countersuit, Musk's team cited Botometer, an online tool that tracks spam and fake accounts, to estimate that 33% of "visible accounts" on the social media platform were "false or spam accounts", much more than the 5% claimed by Twitter.
His lawyers have now also subpoenaed adtech firms Integral Ad Science and DoubleVerify for documents relating to their reviews of accounts or audits of the social media platform's users.
The adtech firms are generally employed by advertisers to independently verify that online ads are viewed by real people and not bots.
In recent weeks, Musk and his team have also demanded Twitter names the employees responsible for calculating the number of bots.
Musk cited fake accounts as the reason he withdrew his US$44bn takeover offer last month, which has prompted Twitter's legal proceedings to try and push the deal through, not just claim the US$1bn break clause.
Botometer creator Kaicheng Yang told the BBC the 33% claim "doesn't mean anything" and questioned the methodology used by Musk's team.
The tool uses several indicators, like when and how often an account tweets and the content of the posts, but does not claims to give a definitive answer to whether an account is a bot or not.
Yang says Musk's countersuit does not explain how it reached the 33% claim, which could mean a lower threshold was used to find more bots than a higher threshold.
He said as the countersuit fails to make the details clear, Musk "has the freedom to do whatever he wants. So the number to me, it doesn't mean anything," he said.