It was OKCupid. They used to publish shit like that on their engineering blog, but apparently they've scrubbed that data because ZOMG PROBLEMATIC. Fortunately, the internet remembers.
Yes. He and his people were to be granted safety within the Roman Empire, but part of the bargain was that they were to surrender their arms as they did not wish to have a massive force of foreigners under arms within the Empire. It's debated whether or not there was simply too many of them to stop and search or whether the border garrisons were bribed -- probably both -- but in the end many of them slipped through with their weapons. This was a good thing for them since, as it turns out, they ended up needing them with the Romans broke every promise they made, starved them, and tried to attack the men they sent to negotiate in good faith. I'll let you read the rest yourself to find out how it ends.
Come on, at least make it rhyme...
Hey hey, ho ho... Creepy Uncle Joe has got to go!