Moazzam Begg, 45, was released from the high-security Belmarsh Prison in south London after the Crown Prosecution Service (CPS) said there was insufficient evidence to continue the prosecution at a pre-trial review.
Begg had been accused of funding terrorism in Syria and of allegedly providing terrorist training and instruction between 2012 and 2013.
"I wanted my day in court but I was very happy....I need to reconnect with my family again. I need to understand what it's like to be a free man and I think that it's important to point out some of the Government's failures in its foreign policy and its internal policy - its clear demonising of the Muslim community," Begg told reporters after being released.
"It shows that little has changed since the beginning of the early days of the war on terror and there is not an appetite, there isn't a desire, to try to really understand what's taking place and the more this continues the more it's going to alienate people."
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In a statement, West Midlands Police said new evidence had come to light which had "a significant impact on key pieces of evidence that underpinned the prosecution's case".
Earlier, the British Muslim appeared before the Old Bailey via video-link when Justice Wilkie formally acquitted him of all charges.
The CPS had alleged he had provided terror training and instruction between October 9, 2012 and April 9, 2013 and was charged with being "concerned in a terrorist funding arrangement" between July and August 2013.
"When Mr Begg was charged with a number of offences earlier this year the Crown Prosecution Service were satisfied there was sufficient evidence to afford prosecution," prosecutor Christopher Hehir told the court.
"The prosecution therefore offer no evidence," he added.