There are two separate issues here. One is the general quality of information on the internet, which I think most people are now aware is of dubious reliability . This doesn't just apply to music attributions but across the board. Anyone can put information on the internet, but often it is wrong - sometimes this is an innocent mistake, sometimes just laziness, sometimes it is malicious. The problem is there is no way of knowing what is correct and what isn't. I fear you are fighting a losing battle trying to stop incorrect attributions from appearing in Google searches, if you correct one entry in Discogs it won't prevent a mistake appearing the next time a recording is entered, and of course there are many other similar sites.

The other, more important, issue is where royalties are concerned. Here again, mistakes can be made, especially with folk music where the tune probably hasn't come from a published version so information may be lacking. It's up to record companies to submit the correct information to the best of their ability, but the rights organisations are usually pretty good at sorting out mistakes.

I have been guilty myself of incorrect attribution. My band Albireo recorded a track called Graemsay Jig which I had originally picked up by ear in a session. Only much later did I learn its title, and I was unable to find out anything more about it when we recorded it, so we credited it as "Traditional". We were later contacted by the son of the composer, Magnus Leask, who had been the lighthouse keeper on the island of Graemsay in Orkney for several years. Magnus was originally from Shetland, and we then discovered he had been at school with our guitarist's mother, and there is even a school photo of them on a Shetland website.