The United States Postal Inspection Service has been pretty busy lately.

That's because shipments of marijuana being seized in the mail have dramatically escalated in recent years, up over 400 percent since 2007, according to a new report.

There is no better way to ship drugs right now," said San Diego Police Chief William Lansdowne, speaking to ABC News.

ABC's report blames an "increase in demand" for marijuana for the spike, along with better detection methods. The network also carried a photo essay detailing various smuggling techniques.

The announcement would seem to evoke a quote by reporter Peter Guither, who runs Drug War Rant:

Those massive drug seizures you read about in the paper affect traffickers much the same way a DVD shoplifter affects WalMart — an annoyance, but part of the normal cost of doing business.

Some states pushing back against 'legal' pot

Even as the marijuana-by-courier trade appears to be escalating, another trend is developing in communities nation-wide: the consumption of legal herbs with a synthetic cannabinoid additive, essentially as a marijuana replacement that is undetectable by drug tests and, for now, completely permitted by law.

One mixture causing particular ire, known as "K2", was recently banned in two Missouri counties and the entire state of Kansas, according to The Marshfield Mail. It is still largely available in smoke shops. The Mail noted that Missouri politicians were told the herbal blend can cause "seizures, vomiting, agitation and other dangers." A bill has been introduced that would ban "K2" across all of Missouri. A similar effort is underway in Nebraska, but legislators are unlikely to vote on the "K2" ban until their next session, according to

Amid Missouri's debate over "K2", an amendment that would have legalized medical marijuana was introduced and immediately voted down, The Missourian noted.

A similar blend of legal herbs called "Spice Gold" has been riling European politicians for its unlisted chemical content: a compound called JWH-018, which is said to have a stronger but shorter-lived psychoactive effect than THC, the active ingredient in marijuana. Thus far, Germany, Austria and France have banned it, and the U.K. was beginning to take up the issue. "Spice Gold" is also distributed in the U.S. Without the chemical additive, "Spice Gold" is simply chopped up baybean, blue lotus, dwarf skullcap, Indian warrior, lions tail, maconha brava, marshmallow, pink lotus, red clover, rose, Siberian motherwort, vanilla and honey.

Other shipments of "Spice Gold" that have been seized by U.S. authorities were found to contain HU-210, a Schedule 1 controlled substance with a significantly more powerful psychoactive effect than THC, even more so than JWH-018. Unlike every other drug of abuse except marijuana, HU-210 has been found to promote “neurogenesis” — regrowth of brain cells — in the embryonic and adult hippocampus, according to the Journal of Clinical Investigation. Its potential medical properties are currently being studied.

The so-called "Trojan Horse" properties of the "legal" marijuana were first uncovered in Dec. 2008 by THC Pharma, a German laboratory, according to The Guardian.