that shit would drive me crazy. i accept that you're champions of europe if you won the european cup or the champions league, but europa league/uefa cup/conference league/fairs cup/cup winners cup are NOT champions of europe. if you're saying you're champions of europe because you won europa league (spurs) then arsenal are as well because cup winners cup was the 2nd tier that played in the uefa super cup against the european cup/champions league winner. teams that qualified for both uefa cup and cup winners cup picked cup winners cup as the one they would play in.
liverpool, united, chelsea, citeh, forest and villa have every right to sing that shit, but the rest? go somewhere you small time idiots.