How the global market in SIM cards powers fraud and influence
How much does an army of bots cost? A new study reveals how likes and clout are bought

A massive international grey market in mobile phone SIM cards is fuelling large-scale manipulation and fraud online, a University of Cambridge study has found.
The researchers say physical and virtual SIMs from providers like SMSActivate, 5Sim, SMShub and SMSPVA were being used to verify fake accounts on social media platforms and e-commerce services.
“We find a thriving underground market through which inauthentic content, artificial popularity and political influence campaigns are readily and openly for sale,” said Jon Roozenbeek, the study’s co-leader.
Many online platforms require SMS verification when a new account is created, a security measure intended to confirm authenticity and curb the mass creation of fake profiles.
In principle, the check is meant to ensure a human was setting up an account at a service like WhatsApp, Telegram, Facebook, X, Shopify or Amazon.
With grey-market SIMs, however, shady organisations were allowing armies of online bots to be verified so they can masquerade as humans.