A question about the English boot sale and street deals in the US

Are the English and European boot sales suspected to be stolen goods. Friday at work I took my break and was walking to both stretch my legs and get coffee. I saw a guy opening a backpack and showin someone the goods. Tbh I thought it was a drug deal as that’s what usually goes on in that area but no it was clean boxes of seiko, citizen and I don’t know what else was deep in the bag.

My feet stopped moving and I was about to ask the guy to get a look at seikos and citizens ask him about any connects but I could tell the way he was acting the stuff was hot as hell. Probably from the plague of smash and grabs hitting everywhere. I decided not to get involved. I’m not preaching or anything to each his own I just don’t want to get involved with things I know are stolen. I will admit if this continues to happen I may have to stop and gather intel maybe there is a cool seiko, citizen or something Kevin O’Leary would approve of in those bags. I just wonder if I’d look at the watch whenever I wear it and see it being smashed out of a display case. When I do good I feel good, when I do wrong I feel wrong. They will never make a Saint out of me and a few years ago I might have bought the whole bag.

Generally car boot sales in the UK are private sellers, more akin to a collection of yard sales.
There are however some pro sellers at boots sales and markets and some of these may be dealing stolen goods. Generally it’s the exception not the rule at an organised sale I’d say. Sellers of stolen gear are generally selling on the hush hush in side sales to dealers who turn a blind eye to a sprinkling of potentially stolen gear amongst their general stock.

In the most recent “boot sale” thread, the OP did share photos of what the environment looked like. I have always understood them to be how David above described- collection of yard sales. I feel like the phrase “boot sale” is similar to “barn find” in that neither generally include an actual boot or barn- they are just phrases. Here is the recent boot sale thread with two photos from it
https://omegaforums.net/threads/spanish-boot-sale-168005.165088/