I listened to all Dustin Lance Black's blog on surrogacy which you can find on iplayer radio 5
He talked a lot about keeping parents (commissioning) and surrogates "Safe". Meaning he thinks UK law should change to something similar to the law in California where a watertight contract is drawn up before the birth, ensuring commissioning parents are guaranteed ownership of the baby from birth.
I posted this on another thread, sorry for copying it over. I'm lazy. 
Basically when he and Tom Daley had their baby in California the law allowed them to draw up contracts, they took the paperwork to hospital with them, they left the hospital with a baby with their names on the birth certificate. He praises how everyone knew where they stood. The surrogate mother (and her husband), the nurses, Tom and Dustin. The surrogate was protected from them making a last minute decision they didn't want the baby for whatever reason. They were protected from the surrogate making a last minute decision to keep the baby.
He was appalled, arriving in the UK with the baby to have to go through the British court system to officially get a parental responsibility order. (Sorry, I can't remember precisely what it is called). And that someone would visit their home to check everything was in order, with the implication the baby could be taken from them if certain standards or conditions were not met. That it could all take several months during which time they weren't the official parents of their baby.
In some ways I had a certain sympathy with him as presumably the baby is an American citizen, American parent, born in USA, but Tom is British and they want to raise the baby here, and presumably want it also to have British citizenship, so they have to satisfy the British courts.
Which is all a bit of a side issue. But in the UK the children's act protects children. So babies born through surrogacy have some protection which presumably doesn't exist in USA/California in that the surrogate mother, whether or not she is the biological mother, is assumed to be the mother and has parental rights until such time as the commissioning parents have applied for and acquired a parental responsibility order.
I'm not sure how long it takes regular commissioning parents in the UK to get those Parental Responsibility orders in the UK or how stringent any enquiries are (relative to what adoptive parents can expect) but this is what certain people want to do away with. One can but hope that child protection will win.
I recommend listening to his blogs if you want to understand more. They are interesting and informative wherever you stand on surrogacy.