Being one of the resident attorney's here, I'll speak to the issue of inmate first amendment rights.
Inmates do NOT have the same first amendment rights of non-inmates, according the US Supreme Court. There is a long series of cases on the subject, but I think this one spells it out failrly well:
From SHAW et al. v. MURPHY, __ US __, April 18, 2001.
"Prisoners’ constitutional rights are more limited in scope than the constitutional rights held by individuals in society at large. For instance, some First Amendment rights are simply inconsistent with the corrections system’s “legitimate penological objectives,” Pell v. Procunier, 417 U.S. 817, 822, and thus [the Supreme] Court has sustained restrictions on, e.g., inmate-to-inmate written correspondence [citation omitted]. Moreover, because courts are ill equipped to deal with the complex and intractable problems of prisons, Procunier v. Martinez, 416 U.S. 396, 404—405, [the Supreme] Court has generally deferred to prison officials’ judgment in upholding such regulations against constitutional challenge."