If you don't want to see the junk results, then go to LW's menu bar, Tools>Options>Filters>Junk & you'll see 3 options. One is don't show. For more on junk typical files, see autogenerated spam results & also autogenerated mp3 spam results. These types of files are easy to filter out as junk. Once you find them, designate them as junk. The filter is a dynamic learning filter so after a few times of adding from searches, they won't appear again.

No they can't be eliminated from the source. The source are spammers trying to wreck the network.