Ability to trace and debug software on servers is not needed for most users. Giving them right to trace processes may leak information and if ptrace() is vulnerable lead to more problems.
Sptrace is a secure ptrace() Linux Kernel Module (LKM). It limits users’ access to the ptrace() call. It can disable strace (and ltrace) altogether, or if you add a ptrace group to your system, only users in that group will be able to use ptrace() call.