He says some of his friends were killed over the past two years in some of the violence that has accompanied Egypt's revolution. And that he desperately wants those responsible — from the old regime and the current regime — to be punished.
"People died in front of me," he said. "I want justice, this is their right."
It is why, he says, a group of like-minded youth, who participated in many of these protests, started the group known as Black Bloc, now labelled a terrorist organization by the public prosecutor.
That is where the police come in: anyone associated with the group is to be arrested. It's why this young man — whom I will call "Mustapha" — said he didn't want his name or whereabouts revealed.
At this point it is difficult to verify much about Egypt's most talked about post-revolution phenomenon, which borrows its name and protest tactics from the anarchist Western version that sprang up in Europe during the anti-globalization protests in the 1980s and '90s.
All we really know is that it exists, in some form, that its members wear masks and generally dress in black, and that they played a role in some recent acts of defiance.
Those who claim membership insist their target is the regime of President Mohammed Morsi and the Muslim Brotherhood, and that violence is a last resort.
"The way to get the message across is to start stopping traffic, striking in sensitive places," says Mustapha. Tactics might even go as far as breaking a window, but not hurting or terrorizing people, he said.
"We want punishment [meted out] but not civil war. So it's now a big problem," he acknowledged. "We need the people to be with us."
He also says, though, that "if we want violence, we can do it. If we get justice, we will all just go home."
Mustapha says Egypt's Black Bloc is not a huge group, perhaps numbering 100, apparently mostly educated students with means. They named themselves Black Bloc, he added, to scare the regime.
The tactic seems to be working — and has everyone here talking.
The media's intense focus on the group has alarmed many here, who, depending on their political affiliation, suggest the group is either the result of the oppositions' rhetoric (or active encouragement), or the general lawlessness under the current regime.
It can also be seen as reflecting the disappointment to date in Egypt's revolution, including the fact that under the Morsi regime, protests have been ineffectual in bringing about change.
A YouTube video posted last week and purporting to be Black Bloc's "first statement" drives home that point.
In white type on a black background, it says that the group is emerging to face the "fascist, tyrannical regime [of the Muslim Brotherhood.] with its military wing."
A group of masked, black-clad youth are then shown walking in a nighttime video that's been slowed down, pumping their fists downward to angry music.
The comments that accompany the video reflect a sharp exchange between supporters and detractors, rife with expletives, and similar to many real-life conversations here in Egypt.
The Black Bloc has been described as a militia, blamed for anti-Brotherhood vandalism — they've been accused of having a hand in attacks against Muslim Brotherhood-affiliated offices last week — but also as revolutionary heroes.
According to another self-described member, who gave his name as "Junior," they're speaking to the media, apparently despite a group rule against it, to correct some of what's been said.
"We are a group who love Egypt and who are against terrorism," Junior said. "We don't have weapons … we are not cutting off roads," he added, which contradicts others who have admitted to doing so.
Yesterday's announcement by public prosecutor Talaat Abdullah was lauded in some quarters, and derided in others — mainly because of how swiftly the designation came at a time when so many other dire security matters seem to receive no official attention. In a scathing online piece, activist and writer Mahmoud Salem (he blogs and tweets as @Sandmonkey) predicted the regime's reaction a couple of days earlier.
"Every regime's purpose is to find a segment of its population to vilify, and thus appear to be fighting the good fight for the good and decent majority," he wrote, pointing out that under the previous regime, that target was the Brotherhood itself.
"The genius of turning the Black Bloc into the new enemy is how perfect they are for it. An anarchist group that targets the police, public structures and roads, juxtaposed against the Brotherhood who are always calling for stability.
"It doesn't hurt that the Black Bloc has no real structure, charter, spokespeople or leadership."
Also, as Salem predicted, there appear to be several groups calling themselves Black Bloc, with different Twitter accounts and Facebook pages (the video mentioned above maintains the group has no such social media sites).
That opens the door to anyone who can don a mask and wear black to shape — or distort — the group's message. But also makes it tough for authorities to know who to arrest.
It was a point made clear by those supporters of Black Bloc who appeared in front of the public prosecutor's office late Wednesday to protest his decision — by wearing black.