Here is a trick i came up with ..

Search for a junk file by typing a bunch of nonsense like "lhfoihasdoifhosdhf;dshf"
Then .. anything that comes back as a positive hit .. right click and chek the box BLOCK IP ADDRESS of that user .. do it several times and you will block the asses that do that .. that is have stuff that makes files based on user searches .. who need that anyway..

Im no pro .. its just my observation