[pmwiki-users] thoughts on blocklist terms (was: Blocklist2 too strict?)

[Neil Herber]

>On Fri, Jul 22, 2005 at 03:23:53PM +0100, K.A.Bouton wrote:
> > How can I make the words blocked less strict
> >
> > For example - the word convert seems to be blocked because of vertin in the
> > sample list?

I have a few suggestions that I find make my blocklist quite effective 
without preventing legitimate posts. These are listed in descending order 
of effectiveness.

1) Block by partial URL. The vast majority of my PmWiki spam was pointing 
to http://?????.??byondart.com/??? so I blocked the URL fragment 
byondart.com .  It is highly unlikely that a spammer will post drug names 
without links - it does nothing to raise their Google ranks. A vandal, on 
the other hand, may just want to deface your site and not post links.

2) Block by IP block. Hovering you pointer over the author name on the 
history page exposes the posting IP (unless you have disabled this 
feature). Just blocking that IP is effective if the spammer has a static IP 
(not likely), so I usually block the entire IP block (do a whois lookup to 
find the boundaries). That way, when the spammer reconnects with a 
different IP from the same provider block, they still can't post. Note that 
this does not prevent anyone in that block from reading - just posting.

3) Add words and phrases to the blocklist. This is generally the least 
effective, because the spammer merely needs to change from "cialis" to 
"cia1is". The shorter the word or phrase you put in the blocklist, the more 
likely you are to get false positives. I try to only use "well known" swear 
words or phrases - ones that are unlikely to be word fragments.


You may wish to provide some mechanism for people to complain if they are 
blocked from posting. I make use of a form that then mails me the 
complaint. I have only ever received 2 complaints in 4 years of 
blocklisting (on a mail server and non-PmWiki websites). The form keep the 
email address hidden from spiders. An example is here:

http://neil.eton.ca/commoninfo/webmastermail.shtml


Neil

Neil Herber
Corporate info at http://www.eton.ca/
Eton Systems, 15 Pinepoint Drive, Nepean, ON, Canada K2H 6B1
Tel: (613) 829-4668