Nearly a quarter of users who follow the electronic cigarette brand Juul on Twitter are under 18, according to a study published recently in the Journal of Adolescent Health.

The latest findings are raising concern not only because the products aren’t intended for underage use, but because many of these youth followers are retweeting the company’s messages.

For the study, researchers [...] analyzed users who engaged with the 3,239 tweets sent by @JUULvapor between February 2017 and January 2018.