I could write two very different posts to this thread, a confrontational and a nonconfrontational. I start with the confrontational:

Some of the posters here don't read what they criticise with enough care and that doesn't help the discussion. Two prime examples are: Brian Clancy, who criticises John Hill for having claimed 'Fiddler's Green' being an Irish song, when in fact John has said explicitely the opposite; and Big Mick who jumps on Hansio and calls him (?) a shallow person for a completely unconfrontational post and doesn't even spell his name correctly. Now to the unconfrontational part.

I see two statements (of purported fact) in John Hill's argument and only one of them can be seen as a reproach:
(1) There are many non-Irish songs in Irish songbooks
(2) They Irish claim them as their songs.
I can hardly see how you can argue with the first claim. If I look at my shelf with English and Irish and Scottish songbooks I can only say this is true. (It is true, I think, as well for e.g. Australia and Newfoundland, but I do not know enough to be completely sure) Why? Perhaps for the same reason why you have a much higher probability to run into a music session in an Irish pub than in an English pub, i.e. Ireland is more open to music, even when it comes from some other place of the world.

I do not see much support for the second assertion. I have songbooks that state 'Irish songs' in the title (or 'songs from Ireland' or parts or Ireland) and they only have Irish songs in them (there are boundary cases everywhere). I see books that are titled 'Songs and ballads popular in the pubs of Ireland' and they for sure have songs among them that are not Irish. I only see one series of books that definitely lies in the title. That is Soodlum's '100 Irish songs' in at least two volumes complete with tape. Of course, they have 'Fiddler's Green' and the other usual suspects, but in each case I have looked at they explicitely state in the notes the author. In one case they even write correctly 'traditional English song' in the notes. You may think it is ironic to be confronted explicitely with a traditional English song in a book titled '100 Irish songs', but at least it's not a lie.

John (Hill), I do not have problems with foreign songs in a collection of songs popular in Ireland, I would have a lot of problems with calling songs trad. that aren't or claiming wrong provenience. However, I do not see a big problem here yet as long as the notes to the songs are correct.

Wolfgang