Hello Pam,
It's not just fraudulent lineages that are the problem?
Unsourced material is surely as problematical, or at least a variation on the same theme?
Interesting that you should post along these lines just now.
Why? Well, because I was thinking about this general problem the other day.
So I Googled.
There's quite an interesting article (not recent - but truth doesn't diminish solely due to the passage of time

)
How to Cite Sources by John Wylie
at
http://www.genealogy.com/19_wylie.html The whole article is worth reading - it's not just 'whether to' (surely a no-brainer) but also 'how to'.
A couple of salient points made by Lt Col Wylie are:
" ... Unless you tell others where you obtained your material, your work is only opinion and weak opinion at that. ... Sources establish credibility. That is, if we fail to cite sources, our friends and relatives may be charitably interested, but others will consider our work a waste of time or, at best, a clue. .. . " Good and succinct comments.
Another good comment which was posted by a respected RootsChatter reads as follows (I don't give the source in case of embarrassing the poster but will freely provide it):
{The etiquette of an online forum is to}
"give solid and reliable replies, offer good information and get good information in return and so it goes. Unfortunately, if these standards aren't applied in an online forum, it is there for all to see and we end up leaving a legacy of unsourced information for future users of Rootschat to stumble upon."We can all make mistakes - but we should all try to be very careful indeed.
Regards,
JAP