Oscy - the wording of the legislation that deals with child protection is that care proceedings should be initiated in cases where a child is "being significantly harmed" or is "in danger of being significantly harmed." Clearly there are numerous ways in which a child can be significantly harmed e.g. physical abuse, sexual abuse, emotional abuse, neglect etc. If a child is physically/sexually abused or negelcted then he is clearly being emotionally abused too.
The thing is that in many cases there is concern about a child/family but there is not sufficient evidence. Yes it is there when there are broken bones, bruises, cuts etc but this is often not the case. Concerns often centre around low level neglect, as in the parent not being physically and emotionally available to a child. In these cases, the soc workers job is to monitor the situation and in the meantime provide whatever support is necessary to improve the family circumstances/parenting and hopefully keep the child within his own family. Sometimes the monitoring goes on too long and the signs are not picked up (as in Baby Peter) and there is a tragedy.
It is a very difficult and stressful job working with these kinds of families and every sw knows a child is best with his own family if at all possible. Most social workers will try anything and everything to prevent having to remove a child and apply to the courts for a Care Order, but sadly that is sometimes the only way to protect a child.
You mention about previous incidents of abuse and neglect and other children being removed. yes of course this has to raise alarm bells and each case is judged individually of course but I can think of many occasions where the only way is to remove a baby at birth from parents where there has been systematic abuse/neglect of other children in the family. If the parents have not been able to improve their parenting ability and as in some cases they are still abusing drink/drugs, then there is every reason to think that the new baby will be in danger of significant harm and the only way to protect him is to remove him from the parents and apply to the courts for a Care Order.
I think the thing to bear in mind is removal of children is always a last resort and the SSD have a duty to provide support in whatever way possible to keep the family together. However when this is patently not keeping the children safe, the bullet has to be bitten and children removed. This of course is just the beginning of the process, as there follows lengthy assessments of the parents by a variety of professionals and the whole matter is heard over several days in court. All professionals will need to be able to evidence in court exactly what they are saying and why they are making a particular recommendation.
It is a lengthy process and the parents are legally represented- their lawyers will be rigorous in their cross examination of all professionals involved in the case and at the end of it all the Judge will make the decision.
There has been a lot of criticism of the system on MN and of course it isn't totally foolproof (nothing in life is) but it's fair and in my experience nobody rides rough shod over the parents. The main thing is that the best interests of the children must be served and yes sometimes this means that parents are angry when their children are not returned to them, but children have a right to live their life free of fear - you only have one childhood.
Sorry too long and a bit rambling but you seem to be asking genuine questions.