Devotees of the Rastafari movement, or Rastas, typically allow their hair to grow naturally into matted clusters known as dreadlocks. Dreadlocks have many important meanings for Rastafarians, but they generally demonstrate an individual's dedication to the faith. Conversely, Rastas associate shaved heads with Western culture, or "Babylon", and the oppression of their spiritual lives and political freedoms.
Prison officials cited cost-savings as their reason for the policy, but never attempted to support the policy with other justifications, not even the safety considerations raised by the possiblity of hidden contraband within the large manes of dreadlocks. Moreover, the affidavit cited by the defendants did not even mention maximum security prisoners. Because of these deficiencies, the court ruled, the correctional officers had violated Smith's rights by shaving his head.
I'd be interested to see what the court had to say about another important part of the Rasta faith, the ritualistic smoking of marijuana. I'd be willing to bet that any panel of federal appellate judges would likely find that a ban on drug use was well within the test the 4th Circuit used today. It would still make for an interesting case, though.
Smith v. Ozmint (U.S. 4th Circuit)
Haircut Violated Rights of Rastafarian Inmate (Courthouse News Service)