A billboard advertising assisted suicide has sparked outrage in Boston, Mass.

The billboard reads, "Irreversible Illness? Unbearable suffering? Die With Dignity."

The sign is the latest billboard in a nationwide campaign by the group calling itself the Final Exit Network.

The group argues that assisted suicide should be an option for people with terminal illness or painful diseases.

"It is possible today for people who have an irreversible illness and who are suffering unbearably to die in just a few moments, peacefully and painlessly," said Frank Kavanaugh, the group's spokesman.

"I think its dangerous to put up signs to encourage people to think this is the option. There's no right to die. There's not a right to demand people to help you kill yourself," said Michael Grodin, a Boston University bioethicist.

Most states outlaw doctor-assisted suicide. But proponents have gained ground with Washington State and Montana voting to legalize the practice just last year.