If a user attempts to gain access to your computer, for example by entering an incorrect password, MacSentry will take note and notify you of how many times access was attempted as soon as you enter the correct password:
 
Note that you may trigger this warning by accidentally entering an incorrect password, so take note of the number of attempts to be sure that someone else did indeed try to access your computer.
Possible Failure Warning
In the unlikely event that anyone does manage to override MacSentry, MacSentry will provide a warning the next time it is launched stating that it was not quit correctly, and thus a breach of security may have occurred:
 
MacSentry will also display this warning if the computer was powered-off or force-restarted while MacSentry was running. Generally, you do not want to see this warning.
Disable Force-Quit Error
MacSentry attempts to disable the standard force-quit command in the Mac OS to prevent a user from forcing MacSentry to quit without entering a valid password. If, however, MacSentry cannot disable the force-quit command, it will warn you ahead of time:
 
See the next chapter for more on MacSentry’s security.