Privacy Breaches: Malicious versions can upload your recovered files to a remote server. How to Get GetDataBack Safely
PhotoRec: A powerful, open-source tool that ignores the file system and goes straight for the underlying data.
Malware Infections: Many "key generators" are trojans in disguise.
For those on a budget, there are several reputable free alternatives that provide similar NTFS recovery capabilities: Recuva: A user-friendly tool for simple file undeletion.