While they doubt Cuba's communist government would risk its rapprochement with the United States by putting former prisoners back behind bars, they say the 53 released are not entirely free.
"It was done with the sword of Damocles hanging over them," said Rafael Molina, a leader of the Patriotic Union of Cuba (UNPACU), the country's largest dissident organization.
About one-third of the 38 people released last week are subject to "conditional release," meaning they must periodically report to the courts supervising their cases, said the dissident Cuban Commission of Human Rights and National Reconciliation.
Another third were released on parole, requiring them to serve out their terms outside prison but unable to leave the country, it said.
Others were simply freed pending trial, with charges still intact, or had their sentences altered.
Virtually all can be returned to jail for minor offenses and some say they were told to stay away from opposition politics.
"None of them have unconditional freedom. None of them," said Elizardo Sanchez, leader of the commission, although he added he did not believe the government would harass them.
Haydee Gallardo, 51, and her husband were among those released last week and she took part in a protest march organized by the Ladies in White group over the weekend.
Though she believes she is one of the few to have no conditions set on her release, she says she worries her husband Angel Figueredo, 53, could be returned to jail.
"I don't think the repression will stop considering that they continue to keep watch over us," Gallardo told Reuters. "I'm afraid the repression will result in him getting locked up again."
Figueredo said he was never told what he could or could not do outside of prison, but that he has received more subtle messages. After leaving the Ladies in White march, he said he saw a state security officer whom he recognized, watching from his car.
"He gave me a threatening nod of the head, but he didn't stop me or talk to us," he said.
Released dissidents often return to their homes stigmatized, enduring suspicions from Cubans who show little or no sympathy for those who openly challenge the one-party system.
They often encounter difficulty finding jobs, and relatives may be declined promotions or coveted spots in universities.
Interior Ministry officials historically have told those on parole not to engage in politics, but many have defied the order without consequence, presuming they are protected by their high profiles.
As part of the deal to restore diplomatic relations after five decades of hostility, the US government negotiated the release of 53 people it considered political prisoners.
Cuba had already released 17 of them by the time the deal was announced on Dec. 17 and has since set free the other 36, plus at least two more who were not on the US list.
Senior US officials have welcomed the mass release.
Cuban officials have said little but they deny the dissidents qualify as political prisoners, instead dismissing them as a tiny minority of mercenaries working for the United States.
While most Cubans support the revolution or are apolitical, there are pockets of dissent, as in David Bustamante's neighborhood in the central city of Santa Clara.
Bustamante, 23, was arrested in May after climbing onto his roof and shouting slogans, demanding that Cuba feed its people.
He was arrested and held for six months before being convicted of public disorder and disrespecting Cuban authorities. One of the 53 on the US list, he was freed on December 9 on conditional release.
Now, he says, he is subject to a curfew and has been warned not to resume political activism.
"I don't feel free," Bustamante told Reuters by telephone. "This is a mockery and it shows they are mocking us. They are snatching our freedom every day because we don't have freedom of expression."
Martha Beatriz Roque, 69, has lived under what Cuba calls "extrapenal license," or parole, for 10 years. She is out of prison but unable to leave Cuba and presumes she is closely watched by state security.
"There are a lot of things you can't do and other things you don't know whether you can do or not," Roque told Reuters. "Those under extrapenal license depend on a judge, to whom you have to report regularly. Those on conditional release are constantly responding to the justice system, any time the system decides."