Yesterday when I was riding the T, the driver twice reprimanded someone for taking a photograph on the train. The first time, a woman with a large SLR was getting her friends to lean together for the shot, but he stopped her just in time.

In case you are unaware, this is part of the war on terror. Despite the fact that about every miniature electronic device now includes a camera, the MBTA forbids any obvious use of photography. Unless you’re willing to spend $375 an hour, in which case you can set up a film crew.

Now more than ever, it’s important to be alert and report suspicious acts to an MBTA official. . . . We rely on your eyes, your ears, and your information related to our security. If you see something, say something.

“Now more than ever”? I guess the idea is the July 7 London bombings put subways in even greater danger. But I don’t think that follows.

For one thing, we’ve been well aware for over a decade that Islamists are interested in attacking anything involving a large number of Westerners: transportation and its infrastructure, skyscrapers, stadiums, water treatment, power plants, and public monuments. Successful bombings may “bring home” the threat emotionally, but its actual probability hasn’t changed.

And these terrorists don’t seem to commit copycat crimes, in the sense of being inspired by others to find new ways to kill. True to the banality of evil, their techniques of destruction are remarkably uncreative. I’m sure the next terrorist incident in the U.S. will not be surprising in the manner of its execution, as horrifying as its results may be.

I also wonder how effective my being alert to suspicious acts is in counteracting terrorism. What suspicious acts would have alerted the fellow passengers in the July 7 bombings? College-age kids with backpacks? Would anything about the clean-cut men in business casual clothes have alerted others on September 11 that they were about to crash several planes into buildings?

It seems as though governmental authorities have responded to recent acts of terrorism with the wrong solution. Keeping box-cutters off planes and locking cabin doors will help to prevent another 9/11 incident (as will the end of the public’s willingness to cooperate with hijackers), but it’s not so clear how the massive bureaucracy of a new federal department or a “threat-level” system helps. Likewise, bomb-sniffing technology at the turnstiles and occasional, random bag searches might deter a subway attack, but not so much the suspicious glances at my fellow passengers.