Unfortunately LW cannot control the content of the files on the network. There is no central server where the files can be managed/filtered/blocked. The files on the network are whatever people decide to share from their own computer. The only files you, I, or anyone else can control, are the ones we decide to share.
There are a lot of mislabeled files on the network. The only way to really know what the file is, is to d/load it and see, but then you'd be breaking the law by having it on your computer. Also there are a lot of videos with young looking actors portrayed as underage teens who are really adults, but not all of them.
You could report them to the the
Internet crime Complaint Center or organizations like the Center for Missing and Exploited Children, or a similar organization in your area.
About all you can really do is filter your search results so those type of files don't show up. You can do that by adding the appropriate words to your keyword filter.
See:
Direct instructions to eliminate porn from results