Conversation so far:
When was Generation Y blocked?
On March 26, 2008, Sánchez announced the recent problems accessing her blog appeared to be a deliberate action on the part of government blocking access to her blog Generation Y.
For how long was Generation Y blocked?
Generation Y blog site's issues seemed to be resolved about a year after the site became unavailable.
Who had blocked Yoani Sánchez's blog Generation Y?
Yoani Sánchez said the Cuban government filtered the website from the Internet.
Did the Cuban government ever give a reason for blocking Yoani Sánchez's blog?
Fidel Castro took the opportunity to quote a long excerpt from Sánchez's blog and expressed his disappointment that there are young persons in Cuba today who think as she does.

Question: How did she know it was cuban state security that blocked her?
Self-contained rewrite: How did Yoani Sánchez know it was cuban state security that blocked her?