ZunZuneo, a Twitter-style application designed to get Cubans talking among themselves on their cell phones, has become the latest obstacle to improved relations between Washington and Havana.
Experts in the United States say the failed project, active between 2009 and 2012, should raise serious questions about US policies towards the communist-run Caribbean island.
The US Agency for International Development has (USAID) admitted to building the application so that Cubans, who face strict curbs on expression, could "talk freely among themselves."
White House spokesman Jay Carney described the program as a "development assistance" scheme.
The program was debated in Congress and conducted within US law, said Carney.
He bristled at suggestions that USAID was being used to mount a covert operation aimed at inciting political unrest against Cuba's communist leaders.
Discretion on implementing the program "does not make it covert," Carney said. "USAID is a development agency, not an intelligence agency. Suggestions that this was a covert program are wrong."
- 'Dumb, dumb, dumb' -
But some experts feel differently.
This "wasteful social media project not only failed to achieve their objectives, it also served to maintain heightened levels of conflict between the US and Cuban governments," said Marc Hanson, a Cuba expert at the left-leaning Washington Office on Latin America (WOLA) think tank.
Washington has maintained an embargo on Cuba since 1962, and frigid relations between the two nations represent one of the world's few remaining holdovers of Cold War-era hostility.
For Hanson, there is no doubt that the plan was aimed at destabilizing Cuba's communist regime.
"The internal logic of this is the same of those who support the embargo, who are the ones to seek the regime change -- they believe in initiatives to destabilize the government," Hanson told AFP.
Washington's goal of promoting human rights and improved economic opportunities "would be much better served by ending the embargo on Cuba," he opined.
Republican Senator Jeff Flake, who favors normalizing ties with Havana, wrote on Twitter:
"If there was ever a better case for changing our Cuba policy, I have not seen it. Wow."
Even more emphatic was Democratic Senator Patrick Leahy, chairman of the Senate Judiciary Committee, who on US television succinctly described the program as "dumb, dumb, dumb."
- Cuba's jailed American -
The failed ZunZuneo project may have at least one serious casualty: Alan Gross, a 64 year-old American detained in Cuba in December 2009 for distributing laptops and communications gear to members of the island's small Jewish community for a company that was under a contract with the US State Department.
Gross was convicted in 2011 of crimes against the Cuban state and sentenced to 15 years in prison.
The Gross case has been a major obstacle for Obama in trying to improve relations with Havana.
In April 2008, the government of President Raul Castro allowed Cubans to own cell phones, and by late 2009 ZunZuneo -- a Cuban term for the buzz of a hummingbird -- was taking its first steps via SMS text messaging.
It was then that Cuba detained Gross, yet Washington continued with the project, Hanson told AFP.
The US government "continued to carry on risky activities that, if discovered, would be sure to provoke the ire of the Cuban government, thus potentially further jeopardizing the well-being of Gross," Hanson added.
- Controversy sweeps USAID -
Cuba currently has two million cell phones that serve about 20 percent of the population. Back in 2008 there were only some 330,000.
When ZunZuneo began, it focused on delivering sports scores and weather reports. The system came to have 40,000 registered users before it suddenly vanished in 2012.
ZunZuneo's true ownership was protected through a series of Caribbean-based shell companies.
Despite US the denials, USAID's role in the program could politicize an agency which often relies on the goodwill of foreign governments to carry out humanitarian work.
Although the ZunZuneo program was born and died while Barack Obama was president, US officials say that neither he nor Secretary of State John Kerry -- nor his predecessor Hillary Clinton -- knew about the project.
Cuba Friday demanded Washington cease its "illegal and covert actions" against the communist island nation.
The Cuban Interests Section in Washington -- the office that represents Havana in lieu of a proper embassy -- said that the episode provides "more proof" that the US government "has not given up" on plans to subvert the Cuban government, and that the US goal is to "create situations of destabilization" in the country.