How can I combat spam messages in a medium-sized online community?

Question

I run an online community with over 10k members and frequently get spammed by users sending spam messages to other members in the forms of money scams. They are not sent via robots but by real human beings, probably sat in cyber cafes abroad!!

I currently don't have any concrete measures put in place and am trying to formulate the best mix of measures to combat this successfully, as I know my competitors are having problems and I need to use this to be advantage as a point of differentiation.

Current ideas include:

Limit messages for new members
Report member feature .... 3 reports = automatic account deactivation (but this wont immediately stop the spammer, they can spam hundreds of accounts in a matter of minutes)
some kind of regex that looks for recurring themes among spammers

Not sure what else, any ideas and suggestions will be very much appreciated.

Why "probably [..] abroad"? Racist! – Lightness Races in Orbit Feb 16 '13 at 18:10 — Lightness Races in Orbit, Feb 16 '13 at 18:10

score 1 · Answer 1 · edited Feb 08 '17 at 14:39

1

Obligatory popular cultural reference:

edited Feb 08 '17 at 14:39

Community

1
1

answered Feb 16 '13 at 18:12

Lightness Races in Orbit

378,754
76
643
1,055

score 0 · Answer 2 · answered Feb 16 '13 at 15:49

0

Mollum? "Mollom is a web service that analyzes the quality of content posted to websites. This includes comments, contact-form messages, blogs, forum posts, etc."

http://mollom.com/

They've got a PHP library on http://mollom.com/download.

answered Feb 16 '13 at 15:49

technoTarek

3,218
2
21
25

score 0 · Accepted Answer · answered Feb 16 '13 at 18:20

A few simple tricks that might be of use:

limit the number of messages an account can send per hour (Unless its a reply to a PM they have received)
Make it so users can only PM once their account is X days old or has made X number of forum posts
Have accounts that are less than X days old use a captcha before sending messages
Put any messages that have been sent in a 'pending' queue if the user gets reported (include sent messages into that queue so other users who may have been spammed will not get the message). If they are a spammer after review, kill the account

score 0 · Answer 4 · answered Feb 16 '13 at 18:20

0

You could filter the words and if the filter goes off temporary ban the member.

answered Feb 16 '13 at 18:20

Vlad

795
1
12
35

score 0 · Answer 5 · answered Feb 16 '13 at 18:30

You should take a look at Akismet.

On top of that you should give the users the possibility to flag spam, exactly as stackoverflow does. If you have 10k members, they should be able to filter out spam that passes Akismet very quickly.

Are you worrying about spam links? Do your users have to be able to post HTML/links at all or is plain text sufficient?

How can I combat spam messages in a medium-sized online community?

5 Answers5