We had a huge song banning rampage at one of the camps I worked at 10 years ago, then things settled down for a while, and it seems they are back on a rampage. Songs which have been banned or altered at my camps include:

Titanic
Rainbow Children
One Tin Soldier
A boy and a girl in a little canoe
Louise (the elephant song)
Ann Marie and John Pierre
Dona, Dona
Georgie
I love little Willy
C-H-I-C-K-E-N (the second verse only)
The billboard song
Grandma's in the Cellar
Misty Song (because it makes kids homesick)
Ezekial
Father Abraham
Singing in the Rain
The Zulu King
Wishy Washy Washerwoman
The Buffalo and his Brother
O'Leary

I'm sure there are at least a dozen more, but that's all I could think of.