His greatest coup was in 2001, when Karl conned his way on to Manchester United's official team photo just by walking on to the pitch in full kit, and standing next to Andy Cole.
Time magazine has chosen Pope Francis as its Person of the Year, but I'd like to nominate someone else.
That guy who stood next to Barack Obama at Nelson Mandela's memorial service and spoke gibberish in sign language.
Bravo, sir! Surely there has never been a bigger, better, gutsier display of chutzpah in history? At least not since Gordon Brown said he'd saved the world.
What motivated this comedy terrorist? Maybe he's a crazy fantasist who actually believes he can sign.
A bit like my pal George, who insists that he can move pencils with the power of his mind, and, when you point out that after 10 minutes of concentration and whimpering it hasn't budged an inch, says, "It moved on a subatomic level."
Or maybe he's one of those people who likes to be surrounded by the rich and famous. Perhaps the finest practitioner of this art is Karl Power, the prankster from Droylsden, Manchester, whose expertise is joining photo sessions that he really shouldn't be in.
His greatest coup was in 2001, when Karl conned his way on to Manchester United's official team photo just by walking on to the pitch in full kit, and standing next to Andy Cole.
The players didn't have a clue what was going on but were too polite to say anything. "Me and my mates have been doing things like this for years," said Power, who revealed that it took two years of planning and a military-style campaign to pull it off. An operation worthy of Montgomery.
Alternatively, it could simply be that the guerilla signer saw an opportunity and took it - and is now endlessly re-watching the repeats and laughing his head off.
That's the explanation I like the most, even if it does undermine the sober nature of the occasion that he spoofed. Yes, memorials are supposed to be moments of solemn introspection.
But while the world loves Nelson Mandela, there's no denying that we also love a good hoax. Hence the strange pleasure whenever it turns out that the latest photo of the Loch Ness Monster is actually a bloke in a bath with a green sock on his hand. The joy of the trickster is partly that they break the rules.
A dark confession: I've always admired the grown adults who decide to go back to school. We all know life was at its best when we were in shorts and the only thing we had to worry about was what lesson to skip next. Heck, it might be nice to go back to school and actually learn something this time around.
So whenever I read about a 37-year-old who passes himself off as 16 and ends up getting a couple of good A-levels at his local sixth-form college, I'm secretly jealous.
If only because they always seem to get away with such an obvious fraud: you can easily spot them in the school photos because they're the ones with a bald spot, middle-aged spread and a big grin on their face. And the other joy of a good prank is that it undermines the superciliousness of the rich and powerful. Of course, there are some occasions and professions where snobbery is permitted and you don't want a random member of the public "having a go" for a laugh (please, Mr Power, never spontaneously volunteer to fly a plane or perform heart surgery).
But when a group of politicians are standing around doing their best to look incredibly serious, it's light relief to see their pretensions undermined by a good spoofing. I like to imagine that the sign language for Obama's big speech read something like: "To release the parachute, pull the red cord."
){kind=small}
){kind=small}
){kind=small}
){kind=small}
){kind=small}
){kind=small}
){kind=small}
){kind=small}
){kind=small}
){kind=small}
){kind=small}
){kind=small}
){kind=small}
){kind=small}
){kind=small}
){kind=small}
){kind=small}
){kind=small}
){kind=small}
){kind=small}
){kind=small}
){kind=small}
)
){kind=small}
){kind=small}
)
)
)
)
)
){kind=small}
){kind=small}
){kind=small}
){kind=small}
){kind=small}