Roughly 2,000 years ago, Roman philosopher Lucius Annaeus Seneca wrote to his friend Licinio, “Growth is slow, but ruin is fast.” Twitter has grown a lot in its 16 years, with 229 million active daily users and an oversize footprint in the political debate. But the company risks losing the trust of users and investors if it doesn’t tackle the issue of bots, spam and fake accounts, as well as improve its content moderation processes. Elon Musk has moved these subjects to the fore with his bid to buy the company. Twitter would be wise not to dismiss him.

Twitter estimates that fewer than 5% of its accounts are fake, spammed or automated. It excludes those in its sales pitch to advertisers, labeling the remaining 229 million accounts “monetizable daily active usage or users (mDAU).” It defines these as “people, organizations, or other accounts who logged in or were otherwise authenticated and accessed Twitter on any given day through twitter.com, Twitter applications that are able to show ads, or paid Twitter products, including subscriptions.”

Twitter does not explain its methodology for estimating mDAUs, but most independent researchers estimate the number of fake, spammed or automated accounts to be far higher than 5%. Five years ago, researchers from Indiana University and the University of Southern California estimated the bot population ranges at between 9% and 15%. More recently, Israeli company Cyabra estimated the percentage of inauthentic Twitter profiles at 13.7%; online monitoring platform Bot Sentinel estimates that fakes, spammers, scammers, nefarious bots, duplicates and single-purpose hate accounts on Twitter comprise 10% to 15%.