Hashtag Trending July 21 - Mark Zuckerberg to explain Cambridge Analytica; creators struggle to profit on TikTok; USPS ups its EV purchase

<p><span style="font-weight: 400;">Mark Zuckerberg to explain his alleged involvement in the Cambridge Analytica scandal, TikTok influencers are struggling to profit from the platform, and USPS is increasing its electric vehicle purchases.</span></p>