I've lived in Istanbul for over ten years. I've also lived in Rome for a long time, and elsewhere. My female colleagues in Rome never ceased from complaining of serious harassment, from which I had to rescue them, sometimes dangerously threateningly. My female Istanbul colleagues, both expat and Turkish, almost never. Why?

I would have to disagree, my experience of the Eyup district and the mosque was that it was actually the most friendly and approachable place in Istanbul and so were the people there. I was escorted around the complex by a female guide. Nor is the mosque the fifth holiest place in Islam (there are only three - the mosque in Mecca, the Prophet's mosque in Medina (both in Saudi Arabia) and The Al-Aqsa mosque in Jerusalem). Eyup is a place Muslims choose to visit as the mosque houses the grave of the Prophet Mohammed's standard bearer after which it is named. Being ripped off is symptomatic of most cities that have large tourist populations and the first conversation the locals will have with you is to be wary of exorbitant taxi fares. Most sites within the old parts (Fatih) are within walking distance anyway.

As someone who travels more than a thousand miles to visit Istanbul every year, I have never experienced such a thing - men circling a lady or people yelling at women because they are improperly dressed, some exaggeration maybe? And your experiment is pretty weird, by the way...

Well, I'd agree about the rip-offs, except I have never experienced it so badly and relentlessly as in Istanbul. It actually made life quite miserable and made one reluctant to make almost any purchases without taking a Turkish friend do the whole transaction, which wasn't always convenient.
Regarding the sexual harassment, I have never visited Rome so I cannot make a comparison. However, I can say that I did not have one female friend or colleague, either foreign or Turkish, who had not been sexually assaulted. One friend was very lucky to escape being gang raped and a group of female teachers at the school where I worked were terrified when a group of the local men tried to break down the door of their apartment to get at them. My Turkish flat-mate also received regular harassment on a daily basis, so this is not only a female foreigner experience.
I was informed by my guidebook that Eyup mosque was the 5th holiest in Islam, and it was on that basis that I made the comment. I did visit lots of other mosques though, without incident. As for exaggeration, I can only say it would have been really nice to have had the poster's apparently problem-free stay in Istanbul, but I would strongly recommend any female to be extremely aware and take appropriate precautions.

I also have to disagree. I lived in Istanbul for two years and have been visiting Turkey regularly for 10 years, including travelling around Turkey on loacal transport as a lone female, and did not once experience the kind of harassment you describe. You say you 'did not have one female friend or colleague, either foreign or Turkish, who had not been sexually assaulted'. Do you really mean assaulted? I find this incredible.

Yes Ajem, I do mean REALLY assaulted. The worst experience that I heard of was a friend of mine who was extremely lucky not to have been gang raped. I suppose the most physical thing that happened to me personally (apart from the endemic groping on the bus) was when I took a taxi, in a main city street in the middle of the day. It was raining, and getting in the taxi, I folded up my umbrella. The whole of the trip the taxi-driver kept enthusiastically saying 'siknik, siknik?' (f***) to me (I just pretended not to understand), while simultaneously driving with one hand and reaching behind him to fondle what he thought was my knee, (but was in fact the soggy end of my umbrella), with the other. On coming almost to my destination he decided that maybe something was amiss and turned around to see what it might be. I have to confess at this point to grabbing his wrist, thwacking it with the umbrella as hard as I could and jumping out of the taxi. I also have to be honest and admit to not paying my fare - I am generally an honest person but do not feel remotely unjustified in this case.

Another friend of mine came close to being abducted when a man who had been following her attempted to force her into a taxi, again in the middle of a busy city street in broad daylight. Yet another (Turkish-speaking) friend was grabbed by her coat lapels, thrown against the taxi by the driver and struck. This was because she had finally gotten out of the cab, after repeatedly asking the driver to take her to 'x' place by 'x' route (a route she went every day). He insisted on taking her by a much longer route - a favourite taxi-driver trick which I have had happen myself - and she finally became fed up and got out.

I suppose the worst non-physical thing that happened to me was an incident with the police. I was having a discussion one night with my Turkish boyfriend in the front of his car, this was in a well-lit place just behind the Attaturk centre in Taksim in fact, one one of the main streets there. Both of us froze when the police car drew up. He had to get out to talk to them; he was gone for a long time and I was really frightened, because I'd got a whole month's wages in my handbag and I knew of many other foreigners who'd had incidents with the police. As a matter of routine I'd given him my passport to take with him - all foreigners are obliged to carry the original of their passport with them at all times. After what seemed an age my boyfriend finally came back. He said he'd had to pay a bribe for them to go away, it was put to him something like well the lights on the police car aren't working - something of this nature. The police had examined my passport, said that it was obviously a forgery and that they believed I was a Russian prostitute; they would therefore be taking me to the hospital for an STD exam. Fortunately he managed to negotiate a way out of it. I count myself extremely lucky not to have lost all the money I had with me, let alone have anything else happen, but obviously I was extremely angry and pretty terrified as well I must say. I reported this incident to the British Consulate the next day and they said it was the worst case of police abuse they had yet come across, although I'm certain there must be many more similar such hair-raising incidents of this nature.

Incidentally this passport requirement is a great money-spinner, I was the only person I knew of who did not have a police officer demand my passport and then refuse to give it back until a hefty bribe had been paid. My Chinese room-mate did in fact refuse to pay the bribe, and had to make several visits to a police station over the course of several days to get the passport back, nearly misssing a flight to China in the process.

None of these incidences are unique to Istanbul/Turkey, but I have to admit that the non-stop nature of this kind of harassment just wore one down after a while and took the pleasure out of living there. I adored the food and the history and the architecture - Istanbul was just like living inside a museum. But I really do not think I could ever go back. I've heard also that Egypt has a really bad reputation for harassment of foreign women, and I've known enough people who have experienced it at first hand to be completely put off going. It's not a case of not being travel-wise or having no idea of the local customs and culture, only a dim-wit would not investigate these beforehand, but just being worn down by the hassle to the point where one's quality of life is so negatively affected that there's no option but to vote with one's feet. A real shame.

Being ripped off by taxi drivers or being annoyed by some people is something not only peculiar to Turkey. You can come across this in almost all southern countries. Istanbul is a huge city with a population of about 15 million and you have all kind of people there as in London or any other city whatever that might be. Having lived in Istanbul for ages, I would say that either you were hanging out in ghettos or you are just exaggerating way too much. You had better travel to other southern countries to make a fair comparison. Istanbul, taking its size into account, is a safe city with wonderful historical heritage, culture, people and cuisine.