Published Tuesday, 10 June 2014
Willie Frazer outside court last month. (© Presseye)
He consented to the warning at Belfast Magistrates' Court on Tuesday after prosecutors withdrew a charge of possessing a prohibited weapon.
With all criminal proceedings against the 53-year-old now ended, he vowed to sue the police for alleged false imprisonment.
Mr Frazer, who spent two weeks in custody on charges related to the union flag protests and the Taser seizure, said he has been left bitter and angry at his treatment.
"I'm sick of being pushed around. All through the history of the Troubles we never claimed a penny for the murders and shootings and bombings.
"But now this is the only path I have open to me for redress."
Mr Frazer, from Markethill, Co Armagh, was one of the most high-profile figures brought before the courts amid demonstrations over the decision to limit the flying of the Union Flag at Belfast City Hall.
He had been accused of encouraging or assisting offences by a public address, and taking part in unlawful marches in January 2013.
Last month, a decision was taken to drop the flag protest charges on the basis the evidence was not strong enough.
He was set to fight the remaining allegation relating to the discovery of the stun gun in February 2013.
Mr Frazer has always maintained that he took it from a group of youths to stop any trouble after being asked to intervene by a parent.
But with the case listed for a contested hearing on Tuesday, it was confirmed that the prosecution was withdrawing the charge on the basis that a caution is accepted.
The outcome means he will have no criminal conviction for the incident.
"Instead of giving the Taser to police I threw it in a drawer and forgot about it," Mr Frazer explained outside court.
"Police know well that I have informed them about any dangerous weapons I have come across."
The victims' campaigner said he has also lodged a complaint with the Police Ombudsman's Office.
"Serious questions have to be answered because these charges with so ridiculous," he claimed.
"If it had anything to do with rioting or something that was a legitimate reason for locking me up for a fortnight I would hold my hands up."
He added: "I'm not angry with the ordinary policeman, but those higher up.
"When I was stopped for breaching bail conditions... somebody at a senior level was telling them to make the arrest.
"They can't pass the buck down the line to the man on the beat, the decision was made way above his head."
© UTV News