To be fair I think Linfield probably are the most hated team in that league. Back in 1998 (I think it was that year) Cliftonville drew 1-1 with Glentoran on the final day of the league and needed Linfield to drop points in their match. When the Glens fans were leaving they were wishing Cliftonville fans luck for the result. A common hatred across the barricades.
I went to a number of Irish cup finals in the years they turned into riots (80s). The Linfield fans were fucking horrible bastards.