Purely hypothetically, as I don't have kids - I don't have a problem with family feeding my bub. For instance, if myself and my sister were both breastfeeding, and I'd left my baby with her and it was time for a feed, I'm okay with her feeding my bub.

I'm not really sure how I feel about BM from a stranger though - to me, it doesn't matter how much testing is done, things can slip through or be mixed up. I have certain values, like not smoking, that the doner may not have, KWIM?