It can be done. Sometimes people get a little overzealous about MySpace safety and feel there is nothing they can do to protect their children. It is true that there are dangers and they are very real but you can minimize these dangers greatly.
First, do not overreact when your teen wants to look around a site like MySpace. If you feel your child is too young you can talk about an appropriate age for this type of thing and then always pay attention to how your child is spending time online.
Second, do not pretend that MySpace and other sites like it do not exist. This will not help you in the least and your child will be in even more danger. Find out all you can about MySpace and you will have the right ammunition when you need it.
Third, Let your child know that you are on top of MySpace safety issues and also that you will be checking up on her to see what is going on. You certainly have the right to take a look at any profile that is on MySpace and that includes the profile of your child.
Fourth, if you are absolutely against your child using MySpace you can purchase filters or monitoring applications that will keep your child off sites like MySpace. You do need to be aware that if your child has friends or access to other computers, she may be able to get on MySpace without your knowledge.
The best things you can do to keep your child from MySpace dangers is to have a working knowledge of the site and the dangers, be open with your child, and set limits.