A couple of years ago, the president of Chile was visiting Germany, and as he was educated, when a child, at a Catholic German school he finished his discourse with "Deutschland über alles": It was a diplomatic disaster!
Currently it is isn't forbidden officially by law, but of course you will get a weird look form other people if you sing the first two verses. But today we don't sing the first verse because it isn't actual anymore (we don't have a stateline at the river "Memel" anymore) or the second one because it sounds a bit..."too German".
You can't say the Pledge of Aliegence in public schools with the words "under God" any longer either! This has been going on for a long long time! Not only Germany is being affected but the USA too! The Jews and reds live to undermind our System from within and make the people Conform and become sheep!