Yes, unfortunately child abuse is not something that comes and goes, but it always present in some form or another. Child stars are even more vulnerable because they are exposed to so many different people via television or other media, that they often receive attention from people who they wouldn't normally have encountered, increasing the chances of someone wanting to harm them.
Yes, I believe that child stars in Hollywood are in danger because these children are placed in an adult dominated world and are at risk of being exposed to sick minded individuals. Hollywood child stars are deprived of a normal childhood and most of their friends and peers are far older than they are.
The problem of child abuse in Hollywood is something that can be solved easily. Children cannot fend for themselves. They need adults to guide them through this world so as long as we have responsible adults who want to help these young stars, then there shouldn't be a problem. Do not let those people who like to take advantage of children be in charge of children.
Ever since Corey Feldman was a star, there have been more laws put in place surrounding pedophiles, making it much more difficult for them to be able to commit these crimes without being caught. For this reason, I don't think today's child stars are in the same amount of danger as they were back then. Of course, there will always be some level of danger, but in today's society, it has decreased significantly.