Like everything else online, do your research. I assume we all know plenty of people who have taken online reviews at face value, I have done it myself. Like most other things on the internet, they can be faked. It is sad that people take advantage of good faith systems like this and do not feel the consequences.

Side note: Having the consumer group be named "Which?" and to include the question mark in it makes it jolting to read in the middle of a sentence. I can't tell if I like the name or dislike it a lot.