In cybercrime slang, "fullz" (short for "full information") refers to a complete set of personally identifiable information (PII) used for identity theft or fraud. A file named fullz.txt would typically contain records with details such as:
Possessing, sharing, or trading fullz files is illegal in most jurisdictions under laws against identity theft, computer fraud, and data protection violations (e.g., CFAA in the US, GDPR in Europe, Computer Misuse Act in the UK). fullz.txt
If you have come across such a file:
You cannot control whether a corporation loses your data, but you can make sure that even if you appear in a fullz.txt file, the data is useless to the criminal. In cybercrime slang, "fullz" (short for "full information")