UPDATE: The receiver, Philip Urban, has been caught and charged by transit police.

An alarmed MBTA passenger snapped a photograph Friday of what appears to be two people engaging in oral sex on a T platform and sent to it transit police on social media demanding action. 

"Dear MBTA, I understand you are having financial problems and it is difficult to maintain a broken system, however my tax dollars should be going to pay your police force because I shouldn't have to stand next to a man receiving oral sex," wrote the irate passenger. 

The incident allegedly happened around 7:30 p.m. at State Street station, according to authorities. Transit Police Lt. Richard Sullivan said the agency shares the woman's disgust, and that investigators will exhaust all resources to identify, locate and arrest the suspects.

"We're not going to tolerate this," Sullivan said. "In my 20 years on the job I’ve very rarely encountered something as brazen as this."

“In my opinion they could care less who happened by,” he said. “More importantly, what if a young child came by?”

The pair is facing a charge of open and gross lewdness, which carries a penalty of up to three years in state prison, Sullivan said. They will also be required to go before the state’s sex offender registry board. 

Though transit police appreciate that the passenger brought the incident to their attention, Sullivan said onlookers shouldn’t use social media to alert them to such things, as their Twitter and Facebook accounts aren’t constantly monitored.

The best way to report crimes, he said, is by calling Transit Police directly, or by downloading the department’s See Say app.