AntiLeech is the option.
http://software.anti-leech.com/
Anti-Leech Software has been designed to protect your website against leechers and thieves. We have both free and commersial products available. See a demo of the products.
AL Download Protector
This script can help you protect your downloads against leechers and save you a lot of bandwidth! It is very easy to set up and completely free of charge.
AL Download Protection features:
» Working with Anti-Leech Plugin
» Detailed stats
» Encrypted communication
» Easy setup, XML compatible
» NetPumper compatible
You may not be able to set restriction on no. of times file can be downlaoded but yes u can control your file downlaod links being posted elsewhere.
Check ur traffic stats and I am sure they will sound little scary.You may not be having that many visitors where ur own download page is the referrer or visitor came fom one of ur ages to downlaod.Many will be referrals from various places on net but not urs.Well,thats the problem,people post direct lniks to ur products and if it has something to do with purchase or sale,it may have been cracked,sorry buddy but that could be the case.
AntiLeech can help u in preventing such downloads.So,anyone who wants to download has to be on ur site and also will not be able to use downlaod manager(except Net Pumper which is compatible with antileech).
I am not sure if this version has the feature where you get IP of downloader shown to him and also present to him downlaod link valid for some duration only,so if he posts it elsewhere,it won't work.
Click on BEGIN DEMO,to see how to use it.
Or click here for install instructions:-
http://software.anti-leech.com/install.html
Also,check for Anti-Link
http://www.wakenet.se/des_real/popup_demo/index.php?type=online_al
In case I find more,shall post it here.
mskprathap