Kitkats may be fairtrade on the cocoa but not the palm oil. That's still from unsustainable chopped-down rainforest.
Take a look at the GP vid
It will take 10 years for the rainforest to be destroyed enough to make the orang-utangs extinct. Nestle claim they'll stop using this palm oil in 2015... and Galaxy is the same...
But watching this film, it is talking about child labour farms supplying to fairtrade. Bear in mind that Fairtrade Foundation farms are strictly controlled and the constant audits will pick up those who aren't following the rules. The farmers will constantly try to undermine the rules and therefore the auditing will constantly be picking up people not following the rules. BUT the majority of the farms continue to follow the rules so buying Fairtrade chocolate means that you'll be almost certain that not only is it child labour free, but it follows the other Fairtrade rules:
- Paying at or above the market rate at all times
- Paying an additional premium at all times to put into paying for schools and social development.
On the other hand, buying non FT chocolate means that you're almost 100% certain to be buying chocolate made from child labour farms.
Buying regular chocolate of any kind means you're buying unsustainable palm oil as well. I recommend Green and Blacks (easy to get, but not THE most ethical chocolate, but they use only ethical ingredients), Booja Booja and Couverture. The latter two are palm oil free (proper cocoa butter is used) and they are very ethical.
Don't be put off Fairtrade. It's not perfect but it's a damned site better than the alternative.