Be dare to say NO!
For some people, saying NO seems very impolite. However, we should know when should we say NO.
In my culture, women were taught to be a lady, we must obey what others tell us to do. If we don't like it, just endure it. It's considered as courtesy not to disobey your seniors, and elders.
the sign are posted almost every public area in Taiwan
I don't think this COURTESY should be used in EVERY situation, especially when it against your nature and your willingness.
In some countries, women just endure when sexual harassment happen to them. They think to ask for help or saying NO is inappropriate in public, so they just endure, then they get both phisical and mental injuries.
Endurance won't make inflicters stop but only make them feel they can do whatever they want to you.
When I was little, I were taught (by schoo,TV ads, and parents) that kids should dare to say NO when strangers or anyone tries to so something bad to you or ask you to follow them. (kidnap is also a serious issue in the past) When teachers teache abouth the safety lesson,they would ask their class to say NO loudly together in class as practice.
Now our government release the anti sexual harassment sign stickers to every public association such as schools, department stores, and tranportations. And also advocate people helpping each other when seeing others are suffer from any kind of harassment.
I know sometimes saying NO is very difficult, but mothing is more important than our own safety.