My understanding of the UK situation (not necessarily correct
) is commercially you have to display signs to comply with Data Protection Regulations and can be fined if you fail to do so. Privately, you do not have to erect any signs as you're exempt from Data Protection Regulations as they specifically affect commercial premises UNLESS you capture part of the street or other public spaces in which case you do need signs.
Data protection rules for businesses in recruiting staff, keeping staff records and using CCTV
www.gov.uk
You cannot point a camera into anyone else's home or garden. You cannot intentionally film the street. However, you can capture part of the street if it's incidental to the point of aim on your own property ie you're filming your driveway and the camera view also captures the street. I think there is an onus to minimise the amount of over capture though. As for filming along the street, obviously a no-no, but again you have the right to protect your property so if eg you' suffering graffiti on the side of your garage adjoining the street, then you can probably put a camera looking along the side of the garage provided you aim it to protect the garage and no deliberately catch the street. That's my understanding and a word of warning to anyone reading it, it's not necessarily correct, so it's not advice and if thinking of installing a camera do your own research or get proper legal advice.
ico.org.uk
(Edited and added some links to the UK advice).
As our US and Aus friends can see, the EU is a legal minefield.
Personally, If I were a criminal and saw a sign saying I was being filmed, I come back another day with a balaclava. Talk about giving the criminals the upper hand.