The second time I saw Mariam that day, she was shaking, almost sobbing. Friends were trying to calm her down.

The first time I saw her, she was taking pictures at Cairo’s Tahrir Square. She’s a young but seasoned news photographer from a neighboring Arab country. Mariam has seen a lot. But nothing like this.

I found out later that between the first time and the second time, she was sexually assaulted by a gang of young Egyptian men. They surrounded her on Tahrir Square, the symbol of Egypt’s progressive revolution, prodding, poking and grabbing her everywhere. Another photographer rescued her.

I was off doing what radio reporters do, getting myself into the middle of a streetcorner political debate somewhere else on the huge downtown plaza. So I, too, was surrounded by Egyptian men. Mine were friendly.

Of course they were. I’m a guy.

The extent to which women are targets of assault, harassment and just plain nuisance bothering here is hard to fathom. Every woman I know, whatever her age, appearance, race, religion or background, has been a target. Every one. It’s catcalls in restaurants, whistles and lewd comments on streets — or worse. Much, much worse.

And all the while I walk around wherever I want with no fears and no concerns. So much so that it’s easy for me to forget — and then berate myself for forgetting — that half the people here don’t have that luxury.

Before we get started, two caveats: These are explanations, not excuses — there is no excuse — and female sexual frustration isn’t even on the radar. Egypt is still in the antediluvian mode of blaming women for being attacked, as if they bring it on themselves.

Social scientists say that rape is not a matter of sex, it’s a matter of power. Here, it’s both, and more.

Egypt is described as a “conservative” and “Islamic” society. That means extra-marital sex is forbidden. And while it might be nominally forbidden in Western societies, there’s none of the winking and smiling about it that we know so well. Here, it’s actually forbidden. Women are murdered on mere suspicion of affairs. Men must wait until marriage, sometimes in their 30s or later, because they can’t get married until they can support a wife.

So sexual repression and frustration spill over.

The same rules have been enforced for more than 1,000 years. What’s different now is the surrounding environment. Sex is everywhere.

The simple satellite TV package at my Cairo apartment doesn’t include ESPN, but it does have more than 500 channels. There are some with Islamic preaching, but many more with Western and Western-style movies and programming. There’s an attempt to excise even the mildest of the steamy parts. Movies have innumerable jump cuts from before to after a kiss, and bedroom scenes are cut to the extent that if you don’t know the movie plots ahead of time, they can all seem like “What Just Happened?”

Local commercials include the usual sexual elements, but if there is a scene of a man and woman touching, it often includes a shot of the woman’s hand sporting a wedding ring. The woman’s, not the man’s.

If the object is to remove temptation and suggestion from the screen, it obviously doesn’t, can’t, work. The clear message is that sex is a part of life, but the society doesn’t allow it.

Such distortions can lead to hatred and violence, groping, attacking and rape. The causes are male sexual frustration and powerlessness. Every woman here has suffered from it. I know I wrote that before. It can’t be emphasized often enough.

What’s new is, now women are complaining. Not all, probably not most, but some. It’s because women played a leading role in the popular revolution that ousted President Hosni Mubarak two years ago, demonstrating shoulder to shoulder with men. As protests against the new Islamist regime continue, that’s still the case.

Tahrir Square has become the focus of the worst abuse because of an added element: Cynical power politics.

Dozens of women have come forward with chilling stories about being surrounded, stripped and abused by gangs of men at the square. It began during the 18-day revolt in 2011. The most famous case was the sexual assault on CBS-TV reporter Lara Logan. Her frank report energized other women to speak out.

In recent months, the phenomenon has worsened. Groups have organized to roam the square and protect against sexual assault. Twitter and Facebook groups have been set up as early warning systems, and a website tracks reports of sexual assault in real time with a map.

There are also instances of men forming rings around groups of women to protect them during demonstrations, but then some men break away and attack the women.

It is clear that many of the worst attacks are orchestrated from above to frighten women away from the square and from involvement in protest activity. Exactly what that “above” is remains uncertain, because there have been no credible investigations. Suspects include the Muslim Brotherhood, the Islamist government, the police and lingering pro-Mubarak forces.

Whoever they are, they are just tapping into and taking advantage of the underlying issue — sexual harassment and assault as a societal norm. It is everywhere.

One street I walk down at midnight between my office and my apartment is not well lit. One night I was about 10 meters behind two women. I saw a car drive past them and heard the driver holler something. One of the women turned and shouted angrily at the driver as he sped away. It doesn’t take much imagination to figure out what happened.

A few days later, there was a similar setup — two young women walking in front of me. I figured maybe this time I could help out. Though I no longer look like a linebacker, the presence of any male can be a deterrent.

So I stayed about two meters behind the women, close enough to be noticed but not close enough to intrude, I thought.

One of the women turned and looked at me with a worried frown. I smiled.

A minute later, she glanced back again, frightened, not just worried.

“It’s OK, I’m one of the good guys,” I laughed.

She relaxed, her shoulders loosening, her fists unclenching. She smiled and went back to her conversation with her friend.

Did I help? Probably not. The problem is just too big.