Message "THIS TOO" in console

While playing with fire, I'm getting several messages THIS TOO in the console (but not in output-server.log or output-client.log), that looks like a forgotten debug message.

2013-03-04 23:47:01 [SERVER] [INFO] Saving and pausing game...
2013-03-04 23:47:01 [SERVER] [INFO] Saving chunks for level 'Test-Welt'/Overworld
2013-03-04 23:47:01 [SERVER] [INFO] Saving chunks for level 'Test-Welt'/Nether
2013-03-04 23:47:01 [SERVER] [INFO] Saving chunks for level 'Test-Welt'/The End
THIS TOO
THIS TOO
THIS TOO
THIS TOO
THIS TOO
THIS TOO
THIS TOO
THIS TOO
THIS TOO
THIS TOO
THIS TOO
THIS TOO
THIS TOO
THIS TOO
THIS TOO
THIS TOO
THIS TOO
THIS TOO
THIS TOO
THIS TOO