Leonid Bershidsky, Columnist

Twitter and Facebook Need a Bigger Cleanup

Even a cautious approach to purging bots and trolls causes investors to freak out. So why not take decisive action?

No. 1 fan.

Photographer: Eric Baradat/AFP/Getty Images

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The plunge of Facebook and Twitter shares in the last two days shows that both companies are hostages to investors’ unrealistic perceptions of how quickly they should grow even as they purge bots and trolls. Moving to eliminate all fake and malicious accounts, as well as making new ones very hard to register, would be scary given these inflated expectations.

Facebook fell 19 percent on Thursday after its quarterly earnings announcement, in part because it missed revenue expectations, but also because it showed slower user growth, which the company said it expected to continue. Increasing spending on the platform’s policing also contributed to the gloomy perceptions. At midday Friday, Twitter was down about 19 percent due to similar concerns.