I saw a post earlier (now disappeared) that touched on this subject, so I’d like to issue a warning.
I would like everybody to know that you risk of paying a fine of up to 7,000€ if you are buying those trinkets from those unlicensed vendors, often soliciting tourists in the streets. It almost happened to me a few years ago.
I stupidly bought a few selfie sticks from one of those African guys in Florence city center. Next, after he got my money, he ran away at full speed, and there I am surrounded by 4 policemen in plain clothes who show me the badge and ask for my ID/passport. They (almost) cited me for 1,000€ fine, which they decided not to levy on me after I pretended to be an American tourist who spoke little Italian and knew nothing about this law. So I got away with just a lecture while several other tourists were witnessing the event (it was on Via Calzaiuoli in a July afternoon, no less).
The law (99/2009) was passed in 2009 and it is actually enforced (more on the buyers than on the migrant sellers, who don’t pay anyhow).
So you are free to be sympathetic to those poor vendors as much as you like, but that is what you risk.
https://quifinanza.it/soldi/prodotti-contraffatti-sanzioni-anche-per-chi-acquista/115964/
https://www.investireoggi.it/fisco/venditori-ambulanti-multe/
http://parma.repubblica.it/cronaca/2012/09/10/news/vendita_di_merce_confratta_controlli_e_sanzioni_dei_carabinieri-42269363/
Source:
Italian Public Law 80/2005, later modified by Law 49/2006 and Law 99/2009
which I translated in a comment below.