People who have used content id at media companies said the system works well , but that some individuals who illegally upload videos to youtube have been able to manipulate the soundtrack or video to avoid detection by the system .
But four people , who initially performed poorly and who had had maze-like dreams during non-rem sleep , ( such as hearing the maze 's soundtrack or meeting people along checkpoints in the maze ) , showed a ten-fold improvement over those who didn 't dream about the maze .
