Warm reminder in the MRT (subway) Singapore

1. this video has repeated many times on my rides in the subway of Singapore, and it seemed to be the one and only video presentation. It shows how you can recognise and get alert of any terrorist bombing. Just like any other country, a bad guy should wear a cap and acts like a suspected. If possible, I would further suggest some words be printed on the forehead as "I am a bad guy". 2. Besides the video, another warm reminder for a very board message "staying safe", but the Chinese has another meaning. I wonder why a cross is missed in this warning sign.