A subway commuter Tweeted this morning, "TSA is checking bags at 42nd street subway, wtf is that?" Yes, the Transportation Security Administration is working with the NYPD on subway bag checks. We spoke to TSA spokeswoman Ann Davis, who told us that the TSA is conducting a pilot program with the NYPD:

The Transportation Security Administration (TSA) is partnering with the New York Police Department (NYPD) to enhance existing security measures in NY mass transit system. Using Visible Intermodal Prevention and Response (VIPR) teams, TSA is implementing a pilot program to assist with the screening of passengers' bags. Random and unpredictable security measures, like mobile screening and VIPR teams, can regularly be seen at anytime throughout airports, in rail environments and at mass transit stations across the country. TSA and NYPD continuously work together to strengthen overall security efforts and keep the American people safe.

While the TSA can't offer many details about the program, expect to see TSA workers mostly during rush hours. Earlier this month, it was reported that alleged subway terror plotter Najibullah Zazi was eyeing the 1, 2, 3 and 6 trains for bombings and, a year ago, there was talk of the TSA taking over subway bag search duties from the NYPD.