I bought an S100 for a major trip to South America last February. I took around 1800 photos and the results were everything I had hoped for. My wife made up a large photo book from the results, sometimes using images across 2 pages and the effects were sensational.
As a professional photographer, it does sadden me to see people here writing incessantly about equipment but ignoring that these cameras are tools for photography - the image ought to be what we are aiming for, not the pixel count or wifi ability.
I work as a photographer, taking photos of office buildings and their surroundings for use on letting or sales brochures and websites. My work is mainly in and around London and the M25 region.
In 20 years I reckon I have been questioned or stopped no more than 10 - 20 times by curious individuals.
With the security climate that is prevalent, I can understand why the police and security individuals have issues with people pointing cameras at them and I have found a reasonable explanation allays their fears, while not having to get their permission.
I think the rule must be, be polite, be reasonable and be prepared to see their point of view, while making it clear that you have a legal right to be where you are, doing what you are doing, (assuming you are), and that the photos in your camera are your intellectual property, and if they are taken away, damaged or destroyed, this would be criminal damage or theft.
How you handle the situation will dictate how it ends.