In fact I know people who have been followed  in their cars and the guys show their numbers and follow ladies but never an assault on the road, risky as you can take their license number. I also know women who have been asked how much, they were in shock that  they were suspected to be prostitutes. Another friend had a man get too friendly in the elevator at City Center and wanted to join her wherever she was going she told him to get lost.  All you need to do is get loud if someone acts  inappropriately.  In Kuwait they would follow you home, we were told to drive to a Police Station and that would deter them, Qatar is not as bad, but given their is active prostitution things are changing. I would not let young ladies go in taxis alone here!