Neither border crossings, nor sniffer dogs, nor extensive search efforts by authorities are keeping potheads from their appointed task: getting high.

According to U.S. government officials, more marijuana is now being shipped through the U.S. Mail than in recent memory. The U.S. Postal Inspection Service, whose seizures of marijuana parcels have increased by more than 400 percent since 2007, says increased seizures almost always indicate a much larger crop being shipped.

abcnews.go.com