Cat Ferguson continues her investigation into the drug rehab industry with a look into how marketers use online social media sites like Facebook to find vulnerable — and potentially valuable — targets. In her latest piece for the Verge, Ferguson reports on how some marketers join or start support groups on the platform and trawl them for clients, often without disclosing their financial interest in the treatment center.

Verge illustrations by Laurent Hrybyk.

[Funding for this project was provided by the Ethics and Excellence in Journalism Foundation.]