I was in Penang two years ago. My friend told me that there were many snatch thief and car breaking. He was especially cautious and did not leave valuables in the car. He also took special care to look after his belongings in the food center - in case someone runs away with them.
I was in Penang yesterday. Another friend took me to the food center in Jalan Macalister. She told me that the situation has improved considerably and Penang is now quite safe. She does not have to worry about crime, except in some places that should be avoided.
The improved condition was due to the new Police chief in Penang, who made special effort to deal with the high incidence of crime previously.