A 34-year-old Dublin man has been jailed for four years by the Special Criminal Court for membership of the dissident republican group, the Continuity IRA.
Dermot Gannon gave a clenched-fist salute and shouted: "Up Oglaigh na hEireann, you wankers!" as he was led from the dock.
During the three-day trial, the court heard Gannon was the leader of a weapons-gathering unit of the CIRA and had control over weapons found in Dublin in October 1999.
Members of the Special Branch found an Army uniform, a forged driving licence and four CB radios when they raided Gannon's home on October 16th, 1999.
Gannon, of Wellview Crescent, Mulhuddart, Co Dublin, is the first person to be convicted of membership of an illegal organisation under the 1998 Offences Against the State Act.
Under the Act, a person's refusal to answer Garda questions during interrogation can be used as evidence in court.
In its ruling, the three-judge court accepted the evidence of Chief Supt Basil Walsh that Gannon was a member of the IRA.
However, the court held that the chief superintendent's opinion could have been formed after gardai raided Gannon's home.
The court ruled the items discovered in Gannon's home, as well as his refusal to answer Garda questions, did not form part of their decision to convict.
The court also noted Gannon was given every opportunity to answer Garda questions during interrogation and that the consequences of his refusal to answer questions were explained to him.
Mr Justice Morris, presiding, said Gannon had been convicted on the evidence of Chief Supt Walsh.
He said Gannon could have weakened the effect of such evidence by giving evidence in court, but had declined to do so.
Before sentencing, Det Supt Peter Maguire said the IRA was not a homogeneous organisation and a number of different groups claimed to be the political descendants of the first Dail.
He said Gannon was a member of the Continuity IRA and remained so.