According to Twitter, users may not operate a fake account or pretend to be a public figure or an organization. Money-flipping schemes in which users ask for a small amount of money in return for a larger sum are prohibited, and phishing schemes will count as a violation. To report instances of fraud, users can select "report tweet" from the drop down menu, choose "It's suspicious or spam" and then choose the type of violation.
Twitter might lock accounts that are in violation and require more information, or block them altogether. It may also warn users about potentially unsafe links and delete specific tweets.
The platform has been cracking down on abuse. Early this year it said it saw a 16 percent drop in the number of abuse reports year on year. It has already banned ads for cryptocurrency and previously made efforts to improve its reporting tools. Still, scams like ads for counterfeit goods still show up. While policy changes like these are necessary, it's hard to say if they'll have any meaningful impact.