Plastic crates are useful for all kinds of things, from shipping, storing and organizing goods to making creative crafts like crate-based furniture or unusual light fixtures. But when these crates get swiped from businesses by thieves intent on recycling them for cash, companies get mad — and they're cracking down on would-be crate burglars, according to the Wall Street Journal.

All those plastic crates, which are worth between $3 and $10 each and can be reused many times, add up fast. Grocery chain Trader Joe's reported a loss of $2.5 million in crates over 18 months to the San Bernardino, Calif., sheriff's department. As the cost of petroleum has increased in recent years, petroleum-based plastics have risen in value as well.

It isn't as small and simple as a few crates being stolen at a time, either. A private investigator watched as a rental truck pulled up behind a McDonald's in Baltimore, with a team of people quickly loading hundreds of the crates into the back. The thieves were caught and indicted for the felony offense of stealing not just that load, but $10 million worth from a wide array of businesses.

And the money from the crates is not the only loss.

"There are huge business disruptions when bakers run out of trays," said Robb MacKie, president and chief executive of the American Bakers Association.

Companies like Coca-Cola, Sara Lee and H&S Bakery have teamed up as COMBAT, or Control of Missing Baskets and Trays. The group has hired investigators to find the crooks and is also training employees to guard the crates.

James Rood, the P.I. who caught the Baltimore crate stealers, has transformed from his former blue uniform as a police detective to three-piece suits in his new job working for COMBAT.

"I did shootings, robberies, drugs. [Now] I spend every day of the week on plastic."