After a production server crash, I reviewed the SQL Server logs. I saw 24 TRACEON commands:

DBCC TRACEON 208, server process ID (SPID) 13.
DBCC TRACEON 208, server process ID (SPID) 16.
....
....

Each traceon had a different SPID. Was this done by the system? Or was this done by a person (SA)?
Could this crash the server? The NT logs didn't show anything unusual.