Thanks! That pretty much works like I'd hoped, and it was easy to implement:
$userName = $_SESSION['user'];
$_SESSION['showCat'] = "a|1";
$_SESSION['showCat'] = "a|2";
$_SESSION['showCat'] = "a|3";
default: //This would be the Admin account
$_SESSION['showCat'] = "1|2|3|6|";
The user, once logged in, initially is only able to see his/her events in the Event Manager, which is nice, as it cuts down clutter.
However, if the filter function is utilized, the user is then able to view all categories again, even with showCat hard-coded. Don't suppose there's a fix for that, such as disabling the filter function?
Also, what is $_SESSION['dataMode'] and its possible values?
Thanks again, this is really helpful!