Obfuscating email addresses in mailto: links

Obfuscating email addresses in mailto: links

am 03.09.2007 18:09:52 von Shion

Hi all

The other day, I encountered a site with a mailto link like this:

href="mailto:info@example.com">
info@example.com


Will this actually prevent anything from harvesting the email address?

Thanks

Re: Obfuscating email addresses in mailto: links

am 03.09.2007 18:13:43 von Andy Dingley

On 3 Sep, 17:09, JL wrote:

> Will this actually prevent anything from harvesting the email address?

No, but it will discourage it. Empirical studies suggest that this
simplistic obfuscation does have significant measurable effect on
discouraging the harvesting of new email addresses for spamming.

Re: Obfuscating email addresses in mailto: links

am 03.09.2007 18:34:46 von John Hosking

JL wrote:
>
> The other day, I encountered a site with a mailto link like this:
>
> > href="mailto:info@example.com">
> info@example.com
>

>
> Will this actually prevent anything from harvesting the email address?

Would it prevent *you* from doing so (if you were so inclined)? No
(presumably), because you know what the f codes are and can
translate them back to the real ASCII-style human-readable address. A
computer program would only make it quicker for you.

This example is weaker than some, because the mailto: is not obscured
and an address harvesting program (which is made to do just that) will
see the mailto: and probably grab the rest, too. The spam is on its way!

When I do this, I munge the whole content C of the href="C".

When all or most harvesters are programmed to detect/translate this
kindof munging, the technique will be useless (or worse, because of the
bulk). But right now, I think most of the harvesters just pass right
over, going for the multitudes of more obvious addresses. There's no
shortage of that "low-hanging fruit".

--
John
Pondering the value of the UIP: http://improve-usenet.org/

Re: Obfuscating email addresses in mailto: links

am 04.09.2007 00:55:47 von Andrew

On 2007-09-03, JL wrote:
> Hi all
>
> The other day, I encountered a site with a mailto link like this:
>
> > href="mailto:info@exam
;ple.com">
> info@exampl
e.com
>

>
> Will this actually prevent anything from harvesting the email address?

I have used this technique and it has proved very successful. Because
I am a little lazy I used the following:

http://www.addressmunger.com/

to generate the mess :-) A gentleman named Nikita published a page in
which he spoke of spam / email addresses which is well worth reading:

http://nikitathespider.com/articles/IngenReklamTack.html

All the best,

Andrew

--
Andrew's Corner
http://people.aapt.net.au/~adjlstrong/ubuntu_cli.html

Re: Obfuscating email addresses in mailto: links

am 04.09.2007 04:06:56 von cfajohnson

On 2007-09-03, andrew wrote:
> On 2007-09-03, JL wrote:
>> Hi all
>>
>> The other day, I encountered a site with a mailto link like this:
>>
>> >> href="mailto:info@exam
> ;ple.com">
>> info@exampl
> e.com
>>

>>
>> Will this actually prevent anything from harvesting the email address?
>
> I have used this technique and it has proved very successful. Because
> I am a little lazy I used the following:
>
> http://www.addressmunger.com/
>
> to generate the mess :-)

I use this shell script:

## Convert e-mail address to obfuscated format for web pages
## Author: Chris F.A. Johnson, copyright 2007
w2()
{
w2h=$1
while [ -n "$w2h" ]
do
temp=${w2h#?}
printf "$2" "'${w2h%"$temp"}"
w2h=$temp
done
}

mailto="mailto:"
anchor='"
closetag="
"

url=$( w2 "${1// /}" "%%%x" )
daddr=$( w2 "$1" "&#%d;" )

link="$anchor$mailto$url\"$gt$daddr"

printf "%s\n" "$link"


--
Chris F.A. Johnson
============================================================ =======
Author:
Shell Scripting Recipes: A Problem-Solution Approach (2005, Apress)