DuckDuck's service started adding one or two backup source citations to their 'Search help' service lately. One can check them to see how trustworthy they are.

Of course backup citations can be hard for 'services' breaking copyright laws to train their machines to be thieves. And legally getting into the realm of academic papers could be expensive.

So for them, providing a trustworthy source is hard to do. Actually knowledgeable people are needed to distinguish trustworthy sources. So there are several discernable motivations to just fake it ... if you don't care what you're doing to the innocent.