Visitors need to be aware and alert. 

(a) Ensure the taxi driver turns the meter on when you get in. Some drivers leave the meter on from a previous hire to catch the unsuspecting tourist. (b) Shopping in medenas is a nightmare. Offer only 1/4 of what they ask - works most of the time. Some lose their temper and even insult you when they cannot strike a deal. If you sense a trader is getting intimidating, just walk away. Sensible option to buy from shops though a bit more pricey, goods are reliable.There are some fixed price shops--they may be a better option (c) Some traders may try to win your confidence by saying - oh my father lives in Brighton or my mother is half English, or that he will be coming to UK for a holiday because England is the best country in the world etc. (d) One may be  confronted in the town by a man claiming to be a waiter from your Hotel and is willing to show you around, get good bargains etc. Steer clear - a favourite con. If you book an excursion to the south with a Camel trek in Sahara, there are few things to watch out. Half way through the trek you will stop for a break. As soon as you demount from the Camel, a hawker will come running to you, open a bottle of Coke and thrust it into your hands even before you say no. You will have to fork out whatever he asks. Then a Horseman appears and try and sweet talk you to stroke his horse or take a photo with the horse. Don't be tempted.