To The Moon

Elon Musk's battle with bots on Twitter is personal.

In the three weeks since Mr. Musk cited fake accounts as a reason for putting his planned $44 billion acquisition of Twitter Inc. "on hold," observers and participants in the deal have puzzled over the thinking behind the tycoon's comments. The issue isn't new for Mr. Musk, who has complained for years about Twitter's ability to measure and manage automated accounts on the platform that often produce spam.

Whatever his intention in raising the issue, it is clear that Mr. Musk has had unusually extensive interactions with bots. As a habitual tweeter with more than 95 million followers, the Tesla Inc. CEO likely has far greater exposure and experience with fake and spam accounts than most on the social-media platform, researchers say. One estimate says spam, fake or inactive accounts make up the vast majority of his followers.

Mr. Musk is "an outlier among outliers," said Darius Kazemi, a computer programmer who has spent a decade creating and studying bots and is currently a senior software engineer at Meedan, a technology nonprofit that aims to combat misinformation. "His experience is going to be different from not just the average user, but the average celebrity."

Mr. Musk didn't respond to requests for comment. Twitter declined to comment for this article but has defended its fight against spam accounts.

Researchers say Mr. Musk's prominence and interaction with other users, as well as the topics he tweets about, make him a magnet for people looking to spread spam and other suspicious content. He has tweeted nearly every day for the past four years, and most of his tweets are mentions of or replies to other users, which encourages attention-seekers -- human and bot alike -- to reply to him.

Others with huge follower counts -- such as former President Barack Obama, singer Justin Bieber and soccer player Cristiano Ronaldo -- don't tweet as often or engage as much.

Spam and fake accounts are an industrywide problem and can cause problems for advertisers and bad experiences for users. The accounts can be difficult to detect and are commonly managed by bots, which are computer programs that can automate posts and replies. Many bots have been programmed to achieve illicit goals, such as spreading false information and tricking people into spending money, tech and social-media analysts say, but others have more benign purposes, such as sharing news and weather alerts.