Under what circumstances (if there are any) can a tow truck driver break into a vehicle to "check" the validity of a parking hangtag if he suspects it to be fake? If this is in any way legal, who/what gives them the authority to do so and where can I go to find more information regarding this issue.  If it is, in fact, illegal, what is the right place to file a complaint regarding this matter.

Thanks for your help!