The main problem with all this is that it's the internet we're talking about and, quite often, the gold that's in there is buried under a heap of crap. Try the experiment for yourself:

Do a Google search for a song, being careful to add the word "lyrics" to the search - in the vain hope that you'll find the composer. Not a chance. Try "Somewhere Over The Rainbow lyrics". Virtually every site in the search list will say 'lyrics Israel Kamakawiwo'ole', or 'lyrics Judy Garland', or 'lyrics Eva Cassidy'. The composer? Hardly a mention until you get to Wikipedia...

Any database, or so-called database which has little or no overarching control is bound to be dubious. That's just the way it is.