Travelling Men
I don't know what they called now but it used to be Tinkers or Travellers. The Bleeding Hearts say they get a hard time. Most, I'm sure, are good and decent people. But there are some who want a lifestyle which allows them to vanish overnight. Years ago such a band of such characters set up camp on the common land between two villages in the English Midlands. Their packs of savage dogs made it impossible to use the public right of way linking the two villages. This mob made their living from tarmacking driveways. I heard they showed up at homes of the vulnerable, elderly, stupid and the just plain greedy claiming to have some Tarmac left over from a construction job going on nearby. So, for cash in hand they could lay a new driveway for a bargain price. I wouldn't be surprised if the new driveway proved to be paper thin and cracked open within a month. But that wasn't the worst of what they did. Boiling up bitumen for the Tarmac creates a highly toxic cancer inducing thick tarry sludge. When these people vanished they left the stream between the two villages clogged with a toxic residue.