Changing behavior and changing attitude are not the same thing. If you would like to go e.g. topless, but have concerns about the behaviors or peoples around you then you haven't changed your attitude - but you have changed your behavior. I'm not nit picking semantics as this is really a very important issue in society today -- you cannot derive how people think from how people act.

>Even if it actually happened

You could not believe me (as a random person on the web), but your phrasing implies that you also consider this somehow beyond the realm of possibility. It happened in Athens, if that matters.

>do you seriously feel that this actually works in changing the attitude of a society

Yeah, where's the surprise? Changes in demographics, like an increased presence of people with more conservative values in an area, can, and do, change the attitudes of a society, just like immigration can influence cuisine, music, religion, and other cultural aspects.

It's not beyond the realm of possibility; I recall a convert to Islam (that looked rather out of place with his red hair, etc.) in the UK trying to perform "sharia patrols" in the streets.

I contest believing that young people going to beach in France or Italy would give even passing thought to what these people think or want, because it's completly outside the realm of my experience of the people that I've ever known to go to the beach, ever. A vastly more likely consideration is avoiding unwanted attention from people that approve of mostly undressed girls.

I don't think that you understand (I don't know, maybe you live here?) how socially -isolated- immigrants are.

>I contest believing that young people going to beach in France or Italy would give even passing thought to what these people think or want, because it's completly outside the realm of my experience of the people that I've ever known to go to the beach, ever.

On the beach, no, but it can be a factor on how people dress to go outside on the city, or to avoid certain streets, and so on.