Elon Musk has openly trolled Twitter CEO Parag Agrawal over the company’s approach to anti-spam and bot counting. Earlier, Musk decided to pause the purchase process of Twitter Inc. , requiring independent confirmation that the number of fake or spam accounts on the platform was less than 5% of active users.

Musk said, that his team would randomly select 100 followers to check on Twitter to try to verify or disprove the company’s data on the percentage of fake/spam/duplicate accounts available. In addition, he urged users of the service to independently repeat this process and share their findings.

This prompted Parag Agraval to start an extensive thread on his Twitter, where he tried to explain anti-spam policy.

“First, let me state the obvious: spam harms the experience for real people on Twitter, and therefore can harm our business. As such, we are strongly incentivized to detect and remove as much spam as we possibly can, every single day. Anyone who suggests otherwise is just wrong.

Next, spam isn’t just ‘binary’ (human / not human). The most advanced spam campaigns use combinations of coordinated humans + automation. They also compromise real accounts, and then use them to advance their campaign. So – they are sophisticated and hard to catch,” wrote Agrawal.

He also tried to explain exactly how Twitter verifies users’ accounts to determine if they are genuine and why such verification cannot be done by simply selecting 100 random accounts:

“Each human review is based on Twitter rules that define spam and platform manipulation, and uses both public and private data (eg, IP address, phone number, geolocation, client/browser signatures, what the account does when it’s active…) to make a determination on each account.

The use of private data is particularly important to avoid misclassifying users who are actually real. FirstnameBunchOfNumbers with no profile pic and odd tweets might seem like a bot or spam to you, but behind the scenes we often see multiple indicators that it’s a real person.

Our actual internal estimates for the last four quarters were all well under 5% – based on the methodology outlined above. The error margins on our estimates give us confidence in our public statements each quarter.

Unfortunately, we don’t believe that this specific estimation can be performed externally, given the critical need to use both public and private information (which we can’t share). Externally, it’s not even possible to know which accounts are counted as mDAUs on any given day.”

It seems that this did not convince Musk, because in response he sent the CEO of Twitter a “poop” emoji.

Although it is more likely that Musk is not just trolling, but aims to reduce the cost of Twitter. His announcement to suspend the purchase process has already had a negative effect on Twitter Inc. And as The New York Times writes, at a technology conference in Miami yesterday, Musk told the public that he did not rule out the possibility of buying Twitter at a lower price.