CAIRO - For the last two weeks, Islam Fathy, a 27-year-old member of the Muslim Brotherhood youth, has been sleeping in a different house each night. He worries that if he returns home, he will become the latest victim of the most sweeping crackdown on the Islamist movement in almost a half-century. Fathy had just been speaking in a downtown Cairo press conference that announced a series of fresh protests in support of ousted President Mohamed Morsy. It's dangerous work: He has had to change his mobile number and email address frequently to evade the domestic intelligence agents that he believes are monitoring his communications. But he pledges to continue his activism until the bitter end. "We are not going to accept negotiation unless it's about getting back our president and constitution," he says. If someone gets arrested, you'll find others replacing him. The more dead, the more join. The hit that doesn't kill you makes you stronger. Fathy's tone may be defiant, but those closest to him fear for his safety. In the middle of our conversation, his wife calls in a panic: "She saw me on TV and hadn't heard from me in half an hour, and so was calling to make sure I hadn't been taken," he explains. He adds that she checks in with him every couple of hours, to make sure that he's safe. Though Fathy and young activists like him are determined to press on, there is no doubt that the crackdown has been successful at breaking the Brotherhood's vaunted ability to organize street protests. Since the movement's two Cairo sit-ins were violently dispersed on Aug. 14, at the cost of hundreds of lives, the crowds that have protested the military-backed government have become dramatically smaller. The Friday protests are now just hundreds or thousands strong, and demonstrations are frequently cancelled as security forces block off access to key roads and squares. But even as the mass demonstrations shrink, there is increasing evidence that some individuals are turning to violence. Egypt's interior minister was the target of an assassination attempt on Thursday, Sept. 5, as a bomb ripped through his convoy. A number of police stations across the country have come under fire, while some protesters have been caught on camera wielding guns and swords. A wave of arrests of top Brotherhood officials has left the famously hierarchical organization without a functioning leadership. Hundreds of leaders are now behind bars, including Supreme Guide Mohamed Badie and Mohammed al-Beltagy, the head of the movement's Freedom and Justice Party. Four TV stations seen as sympathetic to the Brotherhood were also shut down this week, a state-run newspaper reported that the government would dissolve the Brotherhood's registered non-governmental organization. "As an organization, I don't think [the Freedom and Justice Party] is functioning," admits Amr Darrag, a former minister under Morsy and one of the few Brotherhood leaders not on the run. If you have most of the leaders in jail how can the party function? At the moment there is no point bringing people together. Darrag, once a central player in the Morsy administration, says he now has no contact with most of his colleagues, who are either hiding or in jail. He has returned to being a university professor and only sees his political counterparts during periodic meetings with diplomats. "The environment is not good for dialogue or initiatives," he adds despondently. It is beyond sad. The lower rungs of the Brotherhood have tried to fill this institutional vacuum by keeping the cause alive on the streets. Sara Omar, 32, another organizer for the "Anti-Coup Alliance," an umbrella coalition of groups opposing the new military-backed government that includes the Muslim Brotherhood, is a software manager who has been part of the movement since the June 30 protests calling for Morsy's ouster. She says Islamist activists feel like they "are being hunted." The pro-Morsy coalition announces the dates of protests -- but only publicizes the starting points of the marches "by word of mouth," Omar says, due to fear of the security forces. The Friday demonstrations in Cairo usually begin following afternoon prayers, at mosques earmarked as being sympathetic to the Brotherhood. Some rallies are disrupted by "popular committees" -- vigilante groups of anti-Brotherhood local residents. At Asad ibn Al-Forat mosque in the Cairo neighborhood of Dokki, for instance, local youth ban anyone with a beard from loitering outside the building on a Friday. About a dozen "committee members," some carrying sticks, gather outside the mosque and forcibly move people on or prevent bearded drivers from parking outside. Many protests now avoid flashpoint squares and state institutions -- organizers are forced to painstakingly check the march routes for rival demonstrators and vigilantes. Already, the crackdown is extending to the younger generation of Islamist activists. Mohamed Soltan, a 25-year-old Egyptian-American who was shot in the arm during the dispersal of the pro-Morsy sit-ins on Aug. 14, was one such organizer detained recently. His family haven't heard from him since was taken by security forces, and his Twitter account has now been closed. "I think our phones are being tapped and some are being followed," Soltan told Foreign Policy shortly before being arrested. Pro-Morsy protesters, however, bitterly refute claims that support for the movement is dwindling. "Our numbers are increasing every day, there are millions on the street in support of what we are doing," maintains Mona Safa, a 40-year-old physician from the Cairo neighborhood of Heliopolis. Safa is taking a break from cheering on an unusual new form of protest -- a convoy of cars beeping their horns and driving around town together. "The country is behind us," she says, "We represent the will of the Egyptian people." But just feet away, local supermarket owner Saad George, 45, has shut the shutters of his shop as the motorcade drives by. "I was afraid there would be violence when they showed up," he says, "We all know what they are capable of."