The 8th International Forum for the Freedom of the \"Cuban Five,\" imprisoned in the United States on spying charges, opened Wednesday in the eastern city of Holguin. More than 380 activists from 47 countries participated in the four-day event, seeking coordinated actions to promote the release of the five Cubans, who were arrested in Miami in 1998, and convicted of spying and given stiff prison sentences in 2001. The participants will analyze the progress of increasing the use of online social networking sites to pressure the U.S. government to allow the jailed men to return to Cuba. Cuba maintains the five men -- Gerardo Hernandez, Rene Gonzalez, Antonio Guerrero, Ramon Labanino and Fernando Gonzalez, did not threaten U.S. national security, which was the main charge against them. It insists they were only monitoring activists in the Cuban opposition, who were planning a violent overthrow of the Cuban government.