Spike in Ecuador Artefact Theft Indicates Growing Trade

Authorities in Ecuador have reported an uptick in reports of stolen historical artifacts, in a sign the highly lucrative transnational crime of antiquities trafficking may be growing in size (Mimi Yagoub, 'Spike in Ecuador Artifacts Theft Reports Points to Growing Trade ' InSight Crime, Tuesday, 15 April 2014).  

in some instances stolen artifacts are sold openly in auction houses in the United States and Europe, and the possibility of reclaiming them is made difficult by a lack of legislation in some countries stipulating that artifacts should be returned if proven stolen. This difficulty is increased by buyers who claim they did not know the piece was stolen and by a lack of witness testimony in many cases. [...] the main markets for South American antiquities are the United States, Switzerland, Italy, France, Germany, Spain, England, Japan and Saudi Arabia

Though lobbyists for the antiquities trade are stubbornly struggling to deny this, UNESCO warns that stolen cultural property often falls into the hands of criminal networks linked to other illegal activities, such as money laundering.

In the face of this challenge, some Latin American countries have made concerted efforts to combat the illegal trade, with Peru praised by UNESCO in March 2014 for its efforts. However, the diversification of criminal portfolios has made cultural property an alluring revenue stream to organized crime, and as noted by Ecuadorean authorities, its nature makes it hard to stop.

Who'd defend buying antiques and antiquities handled by cultural criminals? What kind of people are these involved in the no-questions-asked trade?