Yoani Sanchez is the island's most prominent dissident. She began her activism with a blog and has nearly 600,000 followers on Twitter. She is also on the verge of starting a digital news project.
In recent years, exile groups in Miami also have tried to help Cubans break through the technology divide by sending computers, laptops and flash drives to share information.
Sanchez and others have gone to pains to state they are not backed by the U.S. government.
Analysts say the findings of The Associated Press' investigation mean their work could become even more difficult.