Personally, I feel that social workers are a very much maligned bunch who are often caught between a roc and a hard place, where if they don't do anything they are accused of laziness and negligence, and if they do they are busybodies who are likely to kidnap your kids!
Absolutely true. I really don't envy social workers, who have an incredibly difficult job.
It's, rightly, assumed that parents are able to take care of their children. I would agree with this. The state also has a role in protecting children on a broader scale, which is also important. There are cases where children are, unfortunately, put at risk by either the circumstances at their home, or by members of their family, and this is where social workers come in, and they should.
However, I've made it sound nice and easy. It's a minefield in reality. A lot of instances where social workers are involved aren't related to the adults causing the child harm, at least not deliberately, but the child's coming to harm by complex social circumstances surrounding the family (for example, the family is not financially able to provide suitable accommodation for their children). For more serious concerns, proving that there's been any malicious actions isn't always easy. People criticise social workers easily when they get things wrong - the Baby P case is probably one of the most famous cases where the social services frankly failed the child and, sadly, young Peter died. However, when you try to take children like this out of their homes, there's often protestations.
Some people also get very concerned when social workers start getting involved in their family life, but from my experience with them
social workers really do try their hardest to keep families together. If it's not safe or possible for a child to live with their immediate family, the first course of action is to look at relatives (aunts, uncles, grandparents) as a suitable solution. I know this is difficult for people to believe, because quite a lot of children are taken into the care of the state, but it's a last resort.
And I have to say, I find it comical (but, sadly, not surprising) that the biggest critics of social workers often have had little to no involvement with them!