Hacker, magnified connection to computer, FBI logo connected to computer, packets travel from hacked computer to FBI logo. Definition of computer trespasser: \"A trespasser is any person who accesses a protected computer without authorization. The definition explicitly excludes any person 'known by the owner or operator of the protected computer to have an existing contractual relationship with the owner or operator for access to all or part of the computer.'\" Button: Trespasser Example. Lanes of the Road quadrant displays LE (Law Enforcement).