Chewing Gum
Singapore has one of the cleanest streets in the world. They have huge fines for littering, spitting and smoking in public areas. And selling of chewing gum is totally banned.

Inappropriate Clothes
Wearing revealing clothes is strictly prohibited in many Arab countries. You may be fined for doing that and especially if you're in Saudi Arabia, you'll end up in prison

Stopping on the Autobahn
You are not allowed to run out of gas in Autobahn highway in Germany. You can't even stop there for any reason. You are also not allowed to step out of the car and walk unless you want to get heavily fined.

Cutting A Cactus
These plants are protected by law in Arizona and USA. If you cut them down, you'll be fined and will be even put in prison

Jogging
As surprising as it may sound, Jogging in groups is banned in the East African country of Burundi based on the argument that people use the activity as an excuse to organize "uprisings" and a cover to plan subversive activities.

Living Together Before Marriage
The UAE has a strict code of conduct for this one. If you do so, the police may come to your place and put you in prison. And without a marriage certificate, you can’t stay in a hotel room with your partner.

Celebrating Valentine’s Day
Saudi Arabia and Pakistan have banned their people from celebrating Valentine's day because it is not a part of their culture.

Public Display Of Affection
Kissing in public can get you in trouble if you're in Iran, the United Arab Emirates, Qatar, Pakistan, or Oman. It is considered to be a socially unacceptable behaviour and you just can't do that!

Eating In Public
During the holy month of Ramadan, nobody can eat in the daytime in public in UAE, it is considered inappropriate. Hence, a person who publicly eats or drinks during the day in Ramadan, or encourages the act of eating or drinking publicly, can face imprisonment or a fine, even if they are not Muslims.

Insulting The King
Don't say anything that's disrespectful to the royal family when you're in Thailand unless you want to end up in jail. The King is worshipped there in a way that westerners can hardly understand. And the definition of an insult is further not clear. Stepping on a note with king's image or dropping it accidentally might also land you in jail

Drinking Alcohol
Alchohol is totally against the principles of Islam, so before travelling to any Arab countries, keep this in mind. While it is completely banned in Saudi Arabia, there are strict restrictions on Alcohol in Iran, the United Arab Emirates, Kuwait, Libya, Bangladesh, Sudan, Yemen, the Maldives, and some parts of India.