In the UK, the setup is broadly similar to the US. As the Metropolitan (ie, London's) Police website says
Members of the public and the media do not need a permit to film or
photograph in public places and police have no power to stop them
filming or photographing incidents or police personnel.
[...]
Officers do not have the power to delete digital images or destroy
film at any point during a search. Deletion or destruction may only
take place following seizure if there is a lawful power (such as a
court order) that permits such deletion or destruction.
Although some photographers' experiences suggest that you cannot always rely on any given policeman knowing this.
In France, Wikimedia Commons notes that
Article 9 of French Civil Code states: “Everyone has the right to
respect for his private life”. This is generally considered to
include one's right to the own image, even if it is taken in a public
space.
According to case law and legal doctrine, photographs taken of (one or
more) individuals require authorisation. Just taking someone's photo
without consent (in private or public space) can be considered as an
invasion of privacy and gives them the right to claim for cessation of
the wrongful conduct. Everyone is legally protected from unauthorised
distribution, publication or commercialisation of a picture of
himself. The permission has to be interpreted in a strict way (only to
the extent expressly consented to by the subject)
though it goes on to note that certain exceptions exist (which seem to me primarily to relate to the incidental and minor appearance of individuals in photographs taken in public places). So the scenery is probably OK, but if there are people in your photo, be careful that you are not making them a major feature of the image.
I have been involved in a traffic accident in France, and being uninjured and having followed normal UK practice of photographing everything and everyone from as many angles as possible, was surprised when the attending officer was more upset with me than with any of the drivers. That in the heat of the moment I was unable to remember any of the French verbs related to deleting images, and thus could not promise to immediately rectify the situation, did not help.