From Bloons ShoutWiki
Spam, which Wikipedia defines as "unsolicited or undesired bulk electronic messages", is a common problem with websites that allow posts from the public, such as wikis, guestbooks, forums and so on.
Spam messages often appear nonsensical or off-topic, and they might be written in a foreign language. Usually spam includes links to an external site or sites, which might contain malicious software potentially harmful to your computer. However, not all spam includes links — some spam messages are just plain-text gibberish without any links.
Usually spam messages are left by user accounts which have been registered very recently, usually within the last 24 hours.
Help! I found spam!
If you find spam on a site you are an admin or steward of, delete it and block the user and preferably notify ShoutWiki staff so we can add their details to our spam tools.
If you aren't an admin, let us know by submitting a problem report via the problem report tool.
How can ShoutWiki combat spam?
ShoutWiki has a wide range of different tools to help protect your site. The ConfirmEdit tool adds simple CAPTCHAs to your wiki. If you need to have the CAPTCHA settings changed for your wiki, please contact us.
Another powerful feature is the hidden input field on the editing view and on other forms. Because spamming robots (or spambots, as they are commonly called) automatically fill out whatever fields they see, they will get blocked because the SimpleAntiSpam extension adds a field that users will not see and shouldn't fill out. Since your users will not be affected by this, it only stops automatic spambots.
Spam blacklist is also a standard feature that we offer to you. It prevents adding URLs that are in the global spam blacklist or in the local spam blacklist (MediaWiki:Spam-blacklist). If you need to add a blacklisted URL to an article, you'll need to add it (or ask an admin to add it for you) to the local whitelist page, MediaWiki:Spam-whitelist.
Help! This isn't spam but it gets blocked by a spam filter!
Can I get a spam phrase blocked?
Yes, if it isn't a common one. We obviously cannot block common phrases like "Thank you!" or "Welcome". Chances are that the spammer who spammed your wiki didn't just spam your wiki, but a bunch of other ShoutWiki-hosted wikis too. The sooner you report a spambot to us, the sooner we can prevent it from spamming!
Our commitment to a better, spam-free world isn't just limited to ShoutWiki wikis. Especially smaller wikis without active administrators are very popular targets for spambots. When we find such a wiki, we will promptly try to get in touch with the wiki's administrator(s) or owner(s) to help them better understand the problem and why it's important to get rid of spam.
If you know of a wiki which could do with some tips on combating spam, let us know by contacting us.