There are 'rescues' like it all over the country - can't understand it myself.
I think some of them ask for money to take an animal in (we always ask for help only if we know a cat is having to go into a cattery) , some of them deal with pedigrees in the hope of making money in the selling and I'm sure some supply vivsectionists and the like.
The best thing to do is to approach them as an animal owner, see how far down the line you get with them and then back out by saying you friend has stepped in. If they seem a bit dodgy then put an ad on the site warning people.
In fact it will not hurt to put an ad on warning people that they should be careful where they let their pets go and check out any rescue 'advertising' for animals as how many real rescues need to do this?