restful image url obfuscation and click tracking

I am wondering if anybody out there could explain or provide online examples (yes, I have already done a lot of googling for this) of how to:

1. conceal the images that users are uploading to our site and
2. how to track clicks of those images

I noticed that a popular site out there has the following for an image url:

http://www.populardomain.com/1WeT9/!!eJsdlw!(U开发者_如何转开发~$(KGrHqUH-C0Erf(7o2TVBL!0uFO(8!~~_14.JPG

Can somebody explain what is going on here?

Thanks in advance.

PS - we are using ASP.NET 3.5 / C# and REST to describe image locations

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This looks like an ordinary random file name. REST has nothing to do with this.