He is an imprisoned transgender anarchist, serving 22 years for acts of eco-sabotage. Marius is incarcerated at Carswell in Fort Worth, Texas, a small, high–security facility; he receives few visits, his mail is monitored, and he is intensely socially isolated.
Since he came out, he has engaged in a painfully slow process of medical screenings to see if he will be permitted to have access to the WPATH standards of care for transgendered people (hormones, surgery, and the right to legally change his name to a gender-appropriate one of his choosing). To write to Marius:
Marie (Marius) Mason #04672-061
Federal Medical Center
P.O. Box 27137
Fort Worth, TX 76127