Twitter, Facebook Divergence on Political Ads Shows Tension in Regulating Speech

Twitter and Facebook are staking out starkly different positions about how to handle political ads, but it is unclear how either approach will prevent the spread of misinformation. Some social-media websites have banned ads related to candidates, political parties and legislation. But blocking issues-based advertising, such as ads from advocacy groups or trade organizations, can be hard to enforce, tech executives and media buyers say.