Two medical marijuana providers have accused the U.S. government of civil rights violations in what may be the first lawsuit of its kind in response to a federal crackdown on pot operations across the nation.

The owners of Montana Caregivers Association and MCM Caregivers claim federal raids on pot businesses across Montana in March were unconstitutional, exceeded the government's authority and pre-empted the state's medical marijuana law.

Since then, federal agents have raided two Washington state dispensaries, and federal prosecutors have sent letters of warning to leaders in most of the 15 states with medical marijuana laws.

The lawsuit was filed Tuesday in U.S. District Court in Missoula against the government, Department of Justice, Attorney General Eric Holder and U.S. Attorney for Montana Michael Cotter.

The plaintiffs claim the intent of the raids was to shut down the medical pot industry.

"The federal government has made clear its intent to threaten and eventually eliminate any business or enterprise related to the medical use of marijuana," Christopher Williams of the Montana Caregivers Association and Randy Leibenguth of MCM Caregivers claimed in the lawsuit.

The Department of Justice did not comment when contacted Wednesday. Cotter spokeswoman Jessica Fehr also declined comment, saying the U.S. attorney's office had not been served with the lawsuit.

The woman stands close to a mirror fingering her throat. Then, sweeping back a mane of red hair, she injects heroin into her jugular vein. A nurse keeps an eye on her from behind.

The scene unfolds in North America's first and only legal injection site, promoted by its founders as a safe, humane facility for drug abusers, now facing a court challenge from a government that sees it as a facilitator of drug abuse.

Defenders of the taxpayer-funded site, in a seedy, drug-infested district of Vancouver, British Columbia, say it is a providing a form of health care, and that health care is a provincial matter under Canada's constitution. The federal government counters that its writ trumps provincial rights because heroin is a federally banned substance.

The case opens before the Supreme Court of Canada in Ottawa on Thursday, and has drawn international attention. Insite, as the Vancouver center is called, is the only facility of its kind in Canada. More could open if the top court agrees Insite is legal.

As of 2009, there were 65 injection facilities in 27 cities in Canada, Australia, and western Europe, according to the Canadian Medical Association Journal. The World Health Organization has called them a "priority intervention" in slowing the spread of AIDS via infected needles.

California's attorney general has again come out against the state's same-sex marriage ban, this time telling the state Supreme Court the proponents of successful ballot initiatives do not have the right to defend their measures in court.

Kamala Harris, a Democrat who succeeded Gov. Jerry Brown in January as attorney general, submitted an amicus brief Monday in the ongoing legal dispute over the voter-approved ban known as Proposition 8.

In it, she argued that only public officials exercising the executive power of government have authority to represent the state when laws passed by voters or the Legislature are challenged.

"California law affords an initiative's proponents no right to defend the validity of a successful initiative measure based only on their role in launching an initiative process," Harris wrote.

The question of where the role of ballot measure backers ends is critical to the legal fight over California's ban on same-sex marriages. Both Brown and former Gov. Arnold Schwarzenegger refused to defend the 2008 constitutional amendment on appeal after a federal judge struck it down last summer as a violation of civil rights.

Proposition 8's sponsors asked the 9th U.S. Circuit Court of Appeals to allow them to step in, but the court punted the question to the California Supreme Court earlier this year, saying it was a matter of state law.

A Massachusetts man known for his infomercials touting the purported health benefits of coral calcium and Supreme Greens has pleaded guilty to tax and consumer fraud charges.

Federal prosecutors say Donald Barrett of Plymouth pleaded guilty on Monday to failing to report $573,000 in income from one of the products he sold on television and for marketing a product touted as preventing cancer and arthritis without approval of the Food and Drug Administration.

The 36-year-old Barrett faces up to three years in prison at sentencing scheduled for July 27. The Salem News reports that he is only expected to receive a year under terms of a plea agreement.

Barrett and his lawyer declined to comment after court.