Some misguided programs or guides suggest that this user should be used for untrusted program execution or handling untrusted data. This is bad advice. Services should have their own, dedicated, user account. Even on sites where NFS is not being used, processes run as user nobody or files owned by user nobody may grant far more privileges than expected, especially if two services have been misconfigured in this fashion.

Do not use the user nobody for anything. It is for NFS.

Special values
0: The superuser normally has a UID of zero (0).[10]
−1: The value (uid_t) -1 is reserved by POSIX to identify an omitted argument.[11]
65535: This value is still avoided because it was the API error return value when uid_t was 16 bits.
Nobody: Historically, the user "nobody" was assigned UID -2 by several operating systems, although other values such as 215−1 = 32,767 are also in use, such as by OpenBSD.[12] For compatibility between 16-bit and 32-bit UIDs, many Linux distributions now set it to be 216−2 = 65,534; the Linux kernel defaults to returning this value when a 32-bit UID does not fit into the return value of the 16-bit system calls.[13] Fedora Linux assigns the last UID of the range statically allocated for system use (0–99) to nobody: 99, and calls 65534 instead nfsnobody.