You may have a standard within your organisation for ownership of SQL Agents Jobs. Here’s quick Powershell snippet that you can use to check your server for compliance against your policy. Change the $servers array to contain the names of the SQL Servers you want to query. Change the value for $default_user to the user that is supposed to all jobs. If a job is not owned by this user the text will be coloured red so it’s easier to spot violations.

# Load SMO
[System.Reflection.Assembly]::LoadWithPartialName("Microsoft.SqlServer.Smo") | Out-Null;

# Array containing sql server names
$servers = @("server1", "server2", "server3");
# Your default job owner
$default_user = "sa";

# Process each sql server
foreach($server in $servers)
{
                Write-Host "$server ";
                Write-Host "===============================";
                # Create a SMO server object
                $srv = New-Object Microsoft.SqlServer.Management.SMO.Server $server;
                $jobs = $srv.JobServer.Jobs;
                foreach($job in $jobs)
                {
                                $jobName = $job.Name;
                                $jobOwner = $job.OwnerLoginName;
                                $colour = "Black";
                                # If job is not owned by default user
                                if($jobOwner -ne $default_user)
                                {
                                                $colour = "Red";
                                }
                                Write-Host -ForegroundColor $colour $jobName $JobOwner;
                }
                Write-Host "";
}

The script will output something like below;

server1
===============================
job1 rhys-VAIO\rhys
job2 rhys-VAIO\rhys
job3 rhys-VAIO\rhys
syspolicy_purge_history sa

server2
===============================
job1 rhys-VAIO\rhys
job2 rhys-VAIO\rhys
job3 rhys-VAIO\rhys
syspolicy_purge_history sa

server3
===============================
job1 rhys-VAIO\rhys
job2 rhys-VAIO\rhys
job3 rhys-VAIO\rhys
syspolicy_purge_history sa