COLUMBIA, S.C. (AP) — South Carolina Gov. Nikki Haley is among 10 Republican governors urging the Federal Communications Commission to give states more autonomy in combatting cellphone use by inmates who have them illegally in prison.

Haley on Monday wrote to FCC Chairman Thomas Wheeler encouraging him to give states “flexibility and authority” to deal with the issue, universally seen as a security threat.

States need FCC permission to block cell signals, and Haley has been vocal in her opposition to required FCC approval. Testifying last month at an FCC field hearing in Columbia, Haley said the state had tried multiple other methods, but none are as effective as blocking.

The letter also was signed by governors from Alabama, Georgia, Indiana, Maine, Mississippi, Nebraska, North Dakota, South Dakota and Utah.