This ensures that data in a snapshot is not overwritten until the snapshot is deleted. Previously stored events will be overwritten upon running this command. Bad sectors cannot usually be overwritten, but may contain recoverable information. The data remains on the disk until being overwritten. In this case, any other file will be overwritten with a new file being created. All data on the partition will be overwritten at the block level. For the first payload, any information that the virus has overwritten with zeros is lost. In this way older pages can be logically overwritten without violating the "write once" rule. The input is usually overwritten by the output as the algorithm executes. This data, so long as it is not overwritten, can be recovered. However, the ciphertext was not overwritten. Manual edits of com.apple.PowerManagement.plist also stand the risk of being overwritten. Peter Gutmann investigated data recovery from nominally overwritten media in the mid-1990s. He describes the song as both thrilling and "loosely and horribly overwritten". The gaps in one trace are overwritten by traces of the following sweep.