The MTA had no choice but to ban all political advertising on its trains, buses and platforms. Regardless of rules to ensure fairness, a government agency can't pick the winners and losers in a free-speech contest.

The ban also probably made us a safer.

The MTA made the change last week after a federal judge rightly decided that an ad submitted by the American Freedom Defense Initiative, a pro-Israeli group, was constitutionally protected. The MTA had argued the ad parody -- which read "Killing Jews is Worship that draws us close to Allah," and was attributed to "Hamas MTV" -- was a security risk.

The agency's new policy is to prohibit ads that express religious or political views, or which comment on government policies. The MTA will now only accept ads that have clearly commercial content. Chicago, Los Angeles and Philadelphia have similar rules.

In justifying its ban, the MTA gave a litany of reasons, including providing a "safe and welcoming" environment for employees and customers. It also doesn't want to spend any more time and money fighting Pamela Geller. who's been trying for years to get the MTA to post her anti-Palestinian ads in subway stations. Geller is the provocateur behind the Muhammad cartoon contest in Texas that ended Sunday with the death of two armed jihadis who planned to attack the gathering.

Political ads represent $1 million of $138 million of the MTA's annual advertising revenue. That might be the most surprising fact to come out of this imbroglio. Only $138 million? That's the return on all those captive eyeballs on the subway and suburban railroads, the largest transit system in the nation in the world's greatest city?

The MTA keeps begging for more money from the federal, state and city governments, but it should also step up. Instead of handing over its ad space to an outside agency to sell, why not get more creative? Ask for bids on digital and interactive displays, or give exclusive rights to high-profile stations. Now that the MTA only accepts commercial advertising, it should find a better way to sell it.