Add a BlackList page for listing spammers

[cboos]

What about a read-only BlackList? page, where we could
list the annoying people/bots?

e.g.

 == BlackList ==

 This is a list of known spammers, users/IP numbers:

{{{ users
webd
}}} #users

{{{ ip
}}} #ip

That list would be monitored similarly the same way as
the InterMapTxt page in InterWiki, and we would check
that list before proceeding to any write operation.

In the case of Trac sites running without the wiki enabled,
the content of the BlackList? page would be read from a
configuration section in trac.ini:

[blacklist]
users = webd
ip = 

The advantage of a BlackList? page is obviously that any "WIKI_ADMIN"
can blacklist a spammer, without the need of server restart.

[anonymous]

this is a senseless feature, because most spammers using dynamic IP-addresses.

[cboos]

Right now there's a spammer (bot?) which uses webd as a username.
The BlackList? technique would be useful as an interim measure,
until a more exhaustive protection (as you suggested in #1145)
gets implemented.

[cmlenz]

(Not sure you're referring to with “you”, but for the record I didn't post the above comment.)

But I do agree with the commenter. I don't think we should add spam protection measures that we know aren't helpful in the long run. You know how hard it is to remove features once they've been added, right? ;-)

What we should do, IMHO, is to add extension points that allows plugins to veto wiki and ticket changes. That would allow us (or someone else) to develop a spam-blocker plugin. That plugin could use a simple blacklist, or it could be more extensive (and useful). See also #2176.

Anyway, let's take this to #1145.