Subject: [Asrg] Content filter abuse for censorship

From: Hadmut Danisch <[email-masked]>
Date: Wed, 7 May 2003 10:29:54 +0200

As I stated earlier and in my RMX draft, content filters
are prone to be abused for censorship. 

A few minutes ago I've sent a message to the list and
a few participants about rhetoric style. I guess everybody
will agree that this message was new (freshly created) and
not a kind of bulk mail.

I received an error message from my delivering MTA:

   ----- The following addresses had permanent fatal errors -----
[email-masked]
    (reason: 550 5.7.1 REJECT go away: Sent to DCC)

   ----- Transcript of session follows -----
... while talking to calcite.rhyolite.com.:
>>> DATA
<<< 550 5.7.1 REJECT go away: Sent to DCC
554 5.0.0 Service unavailable

If you read the web page of DCC, then this is not based on 
certain words contained in the message, but on checksums. 
So the error message above can't be caused by the text
of the message. This particular message was reported to the DCC
as being Spam. So every customer of DCC will not receive that
message anymore. The delivery of the message over the list
is slightly delayed. So when list members do receive that message, 
the DCC will already report it as Spam and block it. 

From my point of view this is private censorship and that's why
I don't like those systems. 

Hadmut

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---

From: J C Lawrence <[email-masked]>
Date: Wed, 07 May 2003 02:06:17 -0700

On Wed, 7 May 2003 10:29:54 +0200 

> If you read the web page of DCC, then this is not based on certain
> words contained in the message, but on checksums. 

In practice Vernon is more generous with his definitions regarding what
gets matched and what gets reported than the DCC pages report.  This is
his perogative as a private mail system operator.

> This particular message was reported to the DCC as being Spam. So
> every customer of DCC will not receive that message anymore. 

There is not requirement for sites running DCC to use its as absolute
spam markers.  Most that I've seen use DCC as a hinting mechanism, one
factor among several, not an absolute flag.

> From my point of view this is private censorship and that's why I
> don't like those systems.

I do not think that censorship means what you think it does.  Please
check a good dictionary.

What are you saying here?

  That someone should not elect what mail they are willing to receive or
  not?

  That someone should not state the criteria on which they decide what
  mail to receive or not?

  That someone should not state the actual decisions they made regarding
  mail they receive?

  That someone should not listen to the criteria or decisions another
  makes regarding their mail, and then factor that into their own mail
  policies in whatever manner they wish?

There are slippery free speech issues in here.

-- 
J C Lawrence                
---------(*)                Satan, oscillate my metallic sonatas. 
[email-masked]               He lived as a devil, eh?		  
http://www.kanga.nu/~claw/  Evil is a name of a foeman, as I live.
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---

From: Vernon Schryver <[email-masked]>
Date: Wed, 7 May 2003 07:21:49 -0600 (MDT)

> From: Hadmut Danisch <[email-masked]>

> ...

That is mistaken.  The DCC does not detect spam.  Instead, the DCC
detects bulk mail.  Local whitelists are used to determine whether
mail determined by the DCC to be bulk is solicited or unsolicited.
Sending a message to the DCC says only "this message was awfully
bulky."  Mailing list traffic is also bulky, which is why the sample
whitelists for the DCC include this mailing list.

Only if Mr. Danisch sends the same message to me and to another mailbox
protected by the DCC and only if the message is not whitelisted for
some reason such as coming via this mailing list should the copy to
the other mailbox be rejected.   

Personal mail from Mr. Danisch is not desired in my vincinity if only
to help me not contribute to the tone of this list.  If he will refrain
from trying to send mail to me, he will stop seeing that SMTP rejection
(not "bounce" in the misunderstanding of SMTP of another contributor).

Using the DCC to tag mail as awfully bulky is useful against those
who send the same message from more than apparent sources.  Some people
respond to an SMTP rejection by resending the message from sources
not obviously associated with the first source.  And then there are
spammers who don't care about SMTP rejections but just send many copies.

Vernon Schryver    [email-masked]
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---

From: "Alan DeKok" <[email-masked]>
Date: Wed, 07 May 2003 09:27:49 -0400

> factor among several, not an absolute flag.

  So Vernon has exposed the true intent of DCC: It's a shared system
of filtering material which is objectionable to the participants.

  That intent is light-years away from spam filtering.  Maybe I'll
sign up for DCC, and submit messages I don't like from ASRG.

> I do not think that censorship means what you think it does.  Please

  I've got a bunch (2 linear feet, to be precise).  It's censorship.

  If Vernon wanted to ignore Hadmut, he would simply discard the
message.  Since he has told others about his opinions, and requested
them (through DCC) to follow his example, it's an attempt by Vernon to
censor Hadmut throughout the DCC system.

>   That someone should not state the actual decisions they made regarding

  Don't be an idiot.  This isn't about Vernon discarding Hadmut's
message, or about Vernon telling Hadmut that his message was
discarded.  It's about Vernon telling *others* to discard Hadmut's
message.
 
>   policies in whatever manner they wish?

  Hadmut made no statement about the people who use DCC.  Your
objections are most ingenious: Plausible on the surface, but subtly
missing the point, so as to give a completely distorted view of
Hadmut's behaviour.

> There are slippery free speech issues in here.

  Not in my country.

  Alan DeKok.

---

From: J C Lawrence <[email-masked]>
Date: Wed, 07 May 2003 11:19:02 -0700

On Wed, 07 May 2003 09:27:49 -0400 

> So Vernon has exposed the true intent of DCC: It's a shared system of
> filtering material which is objectionable to the participants.

That's what ___ALL___ public spam filtering systems are, from RBLs to
blacklists, to razor on down.  Is this a revelation?

> That intent is light-years away from spam filtering.  

Hardly.

> I've got a bunch (2 linear feet, to be precise).  It's censorship.

Ahh, another dictionary collector?  I just had to buy another bookcase
to hold mine.

>> That someone should not elect what mail they are willing to receive
>> or not?
>> 
>> That someone should not state the actual decisions they made
>> regarding mail they receive?

> Don't be an idiot.  

<grin>

> This isn't about Vernon discarding Hadmut's message, or about Vernon
> telling Hadmut that his message was discarded.  It's about Vernon
> telling *others* to discard Hadmut's message.
 
Certainly.  That's the fourth question quoted above.  No more, no less.

> Hadmut made no statement about the people who use DCC.  

Neither did Vernon.

> Your objections are most ingenious: Plausible on the surface, but
> subtly missing the point, so as to give a completely distorted view of
> Hadmut's behaviour.

<shrug> It seems fairly clear cut from here.  I can stand up, as others
have, and say, "George Bush is an idiot, don't listen to him!".  Perhaps
I do this on a mailing list using a machine processable form that some
people inject directly into their radio tuning systems -- much as Vernon
is said to have done with DCC.  

Where's the difference?

Some religious orders dictate whom their members may and may not consort
with, what media channels they may receive, etc.  Some members (and
others) of those orders follows those dictates, others variously stray.

What's the difference?

We may not like the choices people make, but they remain their choices,
not ours.

> Not in my country.

Precisely.  I'm not about to dictate American Free Speech models on
Canada or the rest of the planet, or Canadian jurisprudence for that
matter.

<<Actually there free speech issued in Canada as well, but that's a far
different topic>>

---

From: "Alan DeKok" <[email-masked]>
Date: Wed, 07 May 2003 16:05:23 -0400

> blacklists, to razor on down.  Is this a revelation?

  Call me naive, I guess.  People complain loudly when RBLs list
people who haven't spammed, but who engage in behaviours that the the
maintainers of the RBL finds offensive.  This occurs even when the
publicly stated position of the maintainers is that the purpose of the
list is only to block spam.  It seems I was wrong to believe that
abuse of content filtering tools would provoke similar outrage...

  To quote http://www.rhyolite.com/anti-spam/dcc/ ...

   [ information from DCC ] can be used by SMTP servers and mail user
   agents to detect and reject or filter spam or unsolicited bulk mail.

  Dis-ingenious justifications aside, there's no way that a message to
3-4 people about an ongoing conversation can be considered "spam", or
"unsolicited bulk mail."

> is said to have done with DCC.  

  If you request that other people censor their traffic, it's an
attempt at censorship.  If they do censor their traffic as a result of
your request, it's obviously censorship.

  Alan DeKok.