936509 - Automatically disable accounts based on the number of comments tagged as spam

Status: RESOLVED FIXED

(bugzilla.mozilla.org :: Extensions, defect)

Description

[Boris Zbarsky [:bzbarsky]]

There has been a rash of abusive comments in bugzilla recently, apparently due to someone poorly-socialized people disliking Australis.  These comments have absolutely no redeeming value, being mostly strings of profanity and applications of Godwin's Law.

What we've been doing is a really labor-intensive process of hiding the comments by marking them security-private (a hack), disabling the user, pinging #it to do manual SQL stuff to delete the comments, them pinging people to rebuild indices, etc.  This really doesn't scale; this whole thing is being a semi-effective DoS attack on us.

Can we just have some web UI so whenever someone sees a comment like this they can simply nuke it?  I understand that we may need to restrict the list of "someone"s so empowered, but I don't think it should be too restrictive.  Generally, I would think we can trust people with editbugs to not misuse this sort of power...

Thoughts?

Comment 1

[David Weir (satdav)]

I would second this as a whole and for all bugzilla not just Mozilla sites

Comment 2

[David Lawrence [:dkl]]

We have been taking a different approach this week of blocking the accounts from being created before the comments are made. Problem of marking as spam (not that it is a bad idea) is that the email has already been sent to a lot of people before the comment is even marked. Blocking before the comment is made will be better overall. There is a new feature under review now, that got stalled due to other quarterly priorities, that would help with the tagging side of things (bug 793963).

dkl

Comment 3

[Boris Zbarsky [:bzbarsky]]

Preventing is clearly better if it's doable, I agree; we may need both.  :(

Comment 6

[Boris Zbarsky [:bzbarsky]]

And that's why I filed this as a bmo extension, because doing this for Bugzilla in general has been blocked for almost a decade now...

Comment 7

[Justin Dolske [:Dolske]]

Exactly. Bug 936574 has been reopened for dealing with the immediate issue, so let's discuss a more general approach here for BMO.

Comment 8

[Justin Dolske [:Dolske]]

I'd like to see two additions to Bugzilla's UI to help deal with spam and abuse (primarily the low-rate issues we've always had). Distributing power to deal with problems like this is an effective technique that's used by just about every web comment forum.

1) Create a "moderator" group that has the ability to delete comments/attachments and disable users.

Bug 690833 added the ability to restrict additional comments on a bug to only users with editbugs, and bug 871411 created a group granting the privilege to add/remove that restriction. We should broaden the scope of that group to general moderation. Established contributors with a history of responsibility should have access (many-dozens).

2) Give generally established users (editbugs? or broader?) the ability to flag comments as spam/abuse/off-topic. Once a comment (and/or user?) has been flagged N times, it gets hidden by default. Perhaps with N being extra-small for new accounts. The way TBPL Robot comments are suppressed is almost ideal (random example: bug 910521). Basically, a soft-block that enables crowd-sourced moderation. (Presumably moderation would not apply to editbugs users, to limit the possibility of using moderation as an attack.)

#1 should be simple to implement, #2 would need more care.

ISTR that some forums (Reddit? Or was it Slashdot's karma?) basically combine the two, by making a user's moderation power scale according to how others agree... EG, if everything you downvote is also heavily downvoted by others, you're probably a very good moderator. But if your downvotes are being countered by upvotes from others, your judgement is called into question and thus your power is scaled back. That's probably overkill for Bugzilla, though.

One thing this doesn't deal help with is bugmail. I think we'd either have to ignore that problem, or investigate some separate way of automated detection. (Kind of a solved problem for email in general -- bayesian spam filters -- but I'm not optimistic that would work well for bugzilla comments.)

Comment 9

[:glob ✱]

(In reply to Justin Dolske [:Dolske] from comment #8)
> 1) Create a "moderator" group that has the ability to delete
> comments/attachments and disable users.

editing users is already controlled by a group - editusers.
we're tracking development of an extension to edit comments in bug 936165.

> 2) Give generally established users (editbugs? or broader?) the ability to
> flag comments as spam/abuse/off-topic.

you've just perfectly described comment tagging (bug 793963) which already implements this suggestion with the exception of "flagged N times".  comments can only be tagged once, and as soon as a comment is tagged as "spam" (or whatever), it'll be collapsed by default.

my foolishly titled blog post has more info: http://globau.wordpress.com/2012/10/16/coming-attraction-comment-tagging/

bug 793963 already has a patch waiting for review, and addresses the summary of this bug.  while that review has some age on it, recent events have significantly bumped its priority.

> One thing this doesn't deal help with is bugmail.

indeed; these measures are reactive rather than proactive.


rather than track multiple tasks on the same bug, i'm going to morph this bug slightly.

once comment tagging has been implemented, it would then be possible to automatically disable accounts which are clear bugzilla abusers.  i'm picturing a system where we consider a user's age, the number of non-spam comments, and the number of comments marked as spam.  once they hit a threshold they are automatically disabled with a clear message about how to get their account re-enabled if required.

an example would be automatic disabling of users less than 24 hours old who have create at least 3 comments marked as spam, and haven't created any not-spam comments.

Comment 10

[:glob ✱]

Attachment: 936509_1.patch

adds the ability to say "automatically disable a user if they have made X comments, and ALL their comments are marked as spam".

- uses the comment_after_add_tag and comment_after_remove_tag hooks from bug 975943
- users in a specified group are immune from this (default: canconfirm)
- users who are not considered "new to bugzilla" are immune
- comment_count and disable_text are admin configurable parameters

Comment 11

[Ed Morley [:emorley]]

For users that are submitting multiple comments per minute, might we end up in the situation where they've already added N new comments by the time we've tagged the prior ones, so we're always chasing the elusive 100% of comments marked as spam?

Comment 12

[Gervase Markham [:gerv]]

Good point. How about saying that if their first X comments are marked as spam, they get disabled?

Gerv

Comment 13

[Ryan VanderMeulen [:RyanVM]]

Is there a bug for exponentially rate-limiting comments on new accounts?

Comment 14

[Robert Longson [:longsonr]]

More useful if it's X comments in a row perhaps or X comments in a week or day or hour. We sometimes get new users that start OK, things don't go their way because they want something that we're not going to do for them and they then get abusive. Their first couple of comments may therefore be OK.

Comment 15

[Ryan VanderMeulen [:RyanVM]]

I'm not saying it would be a panacea, but it would have helped for attacks like last week's. Also, we could also make it apply to anyone who doesn't have editbugs or something to have some level of vouching play into it.

Comment 16

[:glob ✱]

(In reply to Ryan VanderMeulen [:RyanVM UTC-5] from comment #13)
> Is there a bug for exponentially rate-limiting comments on new accounts?

bug 937821

(In reply to Gervase Markham [:gerv] from comment #12)
> Good point. How about saying that if their first X comments are marked as
> spam, they get disabled?

sounds easy enough, i'll work on that.


there's no need to over-complicate or build a "perfect" system now.  i want to get something functional live asap, and iterate on the design over time if required.

Comment 17

[:glob ✱]

Attachment: 936509_2.patch

changes:
- disable if first N comments are spam
- disable if last N comments are spam

Comment 18

[David Lawrence [:dkl]]

Comment on attachment 8380636 [details] [diff] [review]
936509_2.patch

Review of attachment 8380636 [details] [diff] [review]:
-----------------------------------------------------------------

Hooks already there so need to be removed. Otherwise looks good and works as expected. r=dkl

::: extensions/AntiSpam/Extension.pm
@@ +179,5 @@
> +    }
> +
> +    # check if the last N comments are spam
> +    elsif (!scalar(grep { $_ } @$comments[-$spam_count..-1])) {
> +        $reason = "last $spam_count commennts are spam";

s/commennts/comments/

Comment 19

[:glob ✱]

To ssh://[e-mail]/webtools/bmo/bugzilla.git
   f9c1b97..572c581  4.2 -> 4.2