READ THIS NEXT: USPS Is Making This Unprecedented Change to Service, Starting Today. The USPS deals with millions of people’s mail every single day, so it’s no surprise that they are quick to send out alerts to customers across the U.S. over any number of issues. In May, Postmaster General Louis DeJoy warned the millions that use the postal system that they should prepare to start seeing postage prices increase at an “uncomfortable” rate over the next few years, as the USPS will continue to push for price hikes until it’s more “self-sustaining.“ae0fcc31ae342fd3a1346ebb1f342fcb And just this month, the Postal Service released a notice about animal attacks around the country, warning Americans that they pose a “serious threat” to both the public and postal workers. According to the agency, more than 5,400 postal employees were attacked by dogs in the U.S. in 2021 alone, and the presence of just one aggressive animal could end mail delivery service for an entire neighborhood. Now, there’s a new warning to keep in mind about your mail. In a series of tweets on June 18, the North Precinct for the Portland Police Bureau (PPB) in Portland, Oregon, revealed that they had located a “plethora of suspected stolen property” during a warrant search of a home in the area. Alongside guns and drugs, the department—who worked in collaboration with postal inspectors for the USPS—also seized stolen postal property. “During the search, officers and detectives located … a USPS jacket and hat, stolen social security cards and passports, and mail from over 30 different victims,” the PPB North Precinct tweeted. RELATED: For more up-to-date information, sign up for our daily newsletter. The Portland police did not identify any suspects or confirm whether any arrests were made, according to CBS-affiliate KOIN 6 News. But those connected to the stolen USPS property were likely involved in a major mail scheme, as the officials said they also seized “washed checks” during their search. According to the U.S. Postal Inspection Service (USPIS), check washing refers to the act of someone changing the payment information on a check and fraudulently depositing it. “Occasionally, these checks are stolen from mailboxes and washed in chemicals to remove the ink,” the USPIS, which serves as the law enforcement arm of the Postal Service, explains on its website. “Some scammers will even use copiers or scanners to print fake copies of a check.” The washed checks discovered in the Portland raid are not an isolated event. On June 6, the USPS responded to concerns from Congresswoman Eleanor Holmes Norton, a representative for Washington, D.C., who blasted the agency after receiving news that someone in her congressional district had checks stolen after they put them in a blue USPS collection box. “Thieves changed the payees and dollar amounts on the checks, and tens of thousands of dollars were stolen from my constituent’s account,” Norton wrote in a letter to the Postal Service on May 16. The agency has “seen an increase in mail theft activity over the past few years” in most major metropolitan areas, James Cari, a government relations representative for the USPS, replied in a written letter to Norton on June 6. Earlier this year, the USPIS reported that it had received 299,020 complaints of mail theft between March 2020 and Feb. 2021—which was a 161 percent jump from the prior year. Cari said that inspectors working with the USPIS oversaw 1,079 mail theft cases throughout the country in 2021 and noted that the agency is “prioritizing investigations linked to stolen checks that are subsequently washed, altered, and negotiated for payment.” READ THIS NEXT: USPS Is Getting Rid of This Service, Starting July 10.