[Mailman-Developers] Interesting study -- spam onpostedaddresses...

Damien Morton dm-temp-310102@nyc.rr.com
Wed, 20 Feb 2002 16:37:27 -0500

> Have you seen what slashdot is doing? I think it has promise, 
> because while it's still reversible programmatically, it 
> makes it much more difficult to do. Will they still get 
> harvested? Most likely. But not nearly as quickly as most 
> other sites, and it's going to make the spambots crazy trying 
> to eat each page looking to figure out if it knows which 
> obfuscation to de-obfuscate. 

What exactly is slashdot doing?

As far as I can see thay are using url/cgi encoding in the email
address. This is trivial to circumvent, as is using html entities, or
any other reversible scheme.

The use of images for email addresses is the only scheme that will raise
the cost of harvesting high enough to make it effectively impossible.
You can think of it as either hash-cash for email addresses, or a
reverse turing test, depending on your point of view.