Not to annoy anyone, but to get back to the original question....

Nearly ANY "Irish" song can be offensive to someone. Just as I would not sing Roddy McCorley to a group of Unionists, I wouldn't sing The Sash to a group of Republicans. Well... maybe. Once - just for the craic...

At the same time, some totally innocent songs get categorized as "Catholic" or "Protestant" by certain segments society - particularly in Belfast or South Armagh.

For that reason, my band tends to limit the number of "rebel" songs we do to a handfull - and then typically those of sufficient age or quality where they are simply good songs to do. As a general rule, we try and avoid the "another martyr for Ireland" songs along the lines of Kevin Barry or Boulavogue unless we are playing to a closed audience whose composition we are fairly familiar with. Just as we would probably not mix "Ye Jacobites By Name" with "Hey, Johnnie Cope" when playing to a Scottish audience, unless we knew the audience expectations.