Spam

Spam is the colloquial name for the electronic version of unwanted communication. Unsolicited sales messages are most commonly categorized as spam, but virus-spreading emails and chain emails are also considered spam (in that they are things we would expect a spam filter to attempt to block). Spam is generally a worse problem because it costs the sender next to nothing (especially compared to other forms of unwanted communication, e.g. junk mail and telemarketing, which cost the originator at least a few pennies per contact).

In addition to email, wikis are also vulnerable to "linkspam", where a spammer (usually a 'bot) automatically posts pages of links, either overwriting existing text, adding to it, or creating a new page. This is usually not in an attempt to get anyone to actually visit the sites it is advertising, but rather to drive up their "relevance" to search engines, leading to greater traffic via those engines.

It causes problems in a number of ways, including:

• its sheer quantity often overwhelms the few genuine messages, which can then be overlooked
• even after being filtered, the few remaining spam messages can take significant time to review (to make sure they are not genuine – messages missed by spam filters are often the most genuine-looking) and delete
• spam filters can accidentally delete genuine messages
• human readers may accidentally delete or misfile genuine messages, thinking that they are spam
• accumulating spam messages, if not frequently reviewed and deleted, can overwhelm an email program's database engine and bring it to a crawl

Notes

Terminology is an issue as far as the general category. Do we call it "malicious information"? That can include spam, viruses, really obnoxious advertising (think of certain political ads) in any medium -- but not the vast majority of advertising, which is more along the lines of "unwanted information", and would you really call telemarketing "information"? It could possibly also include such things as gossip, slander, and libel, which are related but perhaps outside the scope of what I'm trying to describe. To include telemarketing, we might use the phrase "malicious communication". Or is "malicious" the right word? Maybe we primarily mean "unwanted" (I'm going with "unwanted communication" for now, even though that could include e.g. contact from a hostile ex-spouse). There may be a whole taxonomy to draw up here, with different attributes applying in different areas. Something to think about.