OK, OK, more about possible Istanbul scams... but trust me these are mere variations of scams practiced in every tourist city in the world.

Taxis: Avoid touts for unlicensed taxis. Be sure your taxi is a yellow taxi with a rooftop "taksi" sign - it will have signage of the sponsoring stand, hotel or whatever. Pirate cabs are nearly always a ripoff, whether in Istanbul or in London. Be wary if a driver suggest you go with his friend instead of him.

Even before entering, ask about how much it is to your destination. A handy taxi fare page is here. The most important thing is to check the meter is zeroed when you enter the taxi and turned on as you begin to roll. Have an idea of where you are going; some drivers will take you the "scenic" ("less traffic!") route - and you will pay more even if you don't see any decent scenery.

In recent times, one had to make sure the meter was set to gündüz (or "1" showed in the rearview mirror integrated meter display) for daytime rides - if it said gece you were being charged higher nighttime rates, and this was often done during daytime. You shouldn't have to worry anymore - it is all the same rate, but some may try to convince you otherwise, only now at night, of course. And they used to try to play games with old and new Lira bills, but I think that's pretty much over by now.

When you hand over a bill and expect change (or not, actually) it can pay to remember the last three digits of the serial number in case the driver tries to claim you gave him "the wrong bill" or insufficient money in a short-change attempt - this may be the single most common taxi scam, and a good reason to travel with change. If the driver asks you if you have change instead of a larger bill be sure to get your original money back before you hand anything else over. Beware of being distracted as you are settling up.

In short, nothing more or less than taxis all over the world (not everywhere, but too many places). Be sure it's a real taxi of course, and be aware the "helpfully"? parked taxi waiting conveniently at the popular tourist spot may be the most likely to rip you off.

Beware of overly friendly people - whilst some folks might be hospitable and friendly, I am always on alert when the usual "what's your name?" and "where are you from?" is asked. Usually you are being set up, and if you accept an invitation without caution, be aware you might get drugged drinks, or even robbed. Don't be paranoid, I have been invited (usually by families) to tea and simit, and enjoyed them on the feribot, for example. But then we were all eating and drinking the same stuff, from the same pot.


Mmm, simit!

Beware of the "let's go have a drink" as stated in this thread: scam - large thugs will materialize about the time a hugely inflated bill is presented. It will be a most expensive, memorable drink. N.B. This is common elsewhere, including Athens.

Using ATMs, be very careful - you may be observed, your movements given co colleagues by cellular phone, then you may be set up for a "spilled sauce" on your clothing wherein "helpful" people materialize and help - themselves! Or, a team will come around the corner and try create a distraction, such as a mock fight, whilst they toss one of their members your way - this chappie is known as "the dip" in classic pickpocket circles, and I have posted previously about this as it happened (well, nearly) to me.

If you ever get in a spot where you are threatened, be compliant and do not attempt to fight back if you are faced with thugs, especially if they are armed.

Is Istanbul dangerous? Not any more or less than other major tourist cities, which attract slime such as these like a magnet. In these places, keep your wits, deploy common sense, carry only what you can afford to lose (in most places a photocopy of passport, some money and one credit card, everything else in the hotel safe or safe deposit box) is a good idea.