Police today renewed their warnings that the panhandlers are "likely to be a scam" after they reappeared on main city retail drags.
The Evening Times revealed police concerns over the beggars in the summer - only for them to move on.
They have since been seen in other Scottish towns and cities.
Today Alan Porte, the chief inspector in charge of Glasgow's city centre policing, said: "Particularly at this time of year, people may consider giving money to a person apparently having no shoes.
"I would say that this is very likely to be a scam, and people might rather consider giving a donation to a registered charity where they can be sure it is going to a worthy cause."
Like most cities, Glasgow tends to see a rise in begging during the festive holiday period - at least partly as a result of the generosity of seasonal shoppers.
This includes both local beggars and organised groups, from south-east Europe, who effectively tour looking for alms.
The barefoot beggars are typically Roma who have travelled from mainland Europe, through Ireland and Scotland.
They usually operate in pairs - with a man begging barefoot while a companion, often a young woman, holds his shoes.
David MacLean, an electrical engineering student from Paisley who works in the city centre, has watched one team in action.
The 26-year-old said: "I find it a disgrace the way these people pretend to be so poor that they don't even have shoes to wear to fool the kind-hearted people who would give them money as they feel sorry for them when really they are just being conned.
"I have seen this guy a few times barefooted and it really annoys me as I know he has a relation nearby with his shoes."
Roma are among the most excluded and vulnerable people in Europe - victims of institutionalised prejudice and economic discrimination - but only a few resort to "professional" begging.
While some barefoot beggars were detained by police in the summer, begging is not against the law in Scotland.
Glasgow and Aberdeen have lobbied the Scottish Government to outlaw begging using bylaws but it has not done so.
Mr Porte added: "There are two distinct groups of people who beg in the city centre.
"There are the regular individuals who, for whatever reason, are down on their luck".
"But there are also people who are actively engaged in begging who are doing it almost as an occupation.
"This is relatively organised. They are often working in pairs.
"One, a man, usually takes his shoes off, rolls up his trouser, crouches down, puts a T-shirt over his knees and shivers and sometimes sobs.
"People naturally feel sympathy for him, think there is something wrong and will then perhaps purchase shoes or food or give them money, vouchers - that kind of thing.