Well, he does look friendly
As Shaker Aamer, the "last British resident to be held in Guantanamo Bay", is released after 13 years, and the media goes into full-blown jubilant celebration mode, please take some time to read this handy summary produced by the Henry Jackson Society back in February of this year, detailing the jihadist activities Aamer is believed to have been involved in - and which have never been disproven - including his terrorist associations and the evidence that he actively fought against Coalition troops in Afghanistan. The short report also debunks some common myths surrounding Aamer and explains why he has been detained for so long despite never being formally charged.
It's conclusions are concise and straightforward:
There is little reason to dispute the US government’s assessment [despite Shaker's claim that he is merely a charity worker ~ Ed] that Aamer is a trained mujahideen fighter who recruits for extremist causes and has wide-ranging connections to al-Qaeda, al-Qaeda-related charities, and known terrorists.
Even if Aamer is released, there should be no illusions over the nature of his past activities and why he was detained at Guantánamo Bay in the first place.
After you've read that, move on and read about this guy, who the British government freed from Gitmo and gave £1 million in compensation...and who has now fled to Syria and joined the Islamic State.
And after you've read that, crack some tunes on and paaaaaaartay!