By Emily Chung, CBCNews.ca

Legitimate businesses could probably learn something from spammers, who often identify new trends and move to exploit them far more quickly than the suit set does.

When the stock market was hot, spammers were sucking in suckers by encouraging them to invest in low-cost stocks the spammer owned shares in to pump up the stock's value. When the market plunged, they started using subject lines that involved mortgage refinancing or debt consolidation. A few weeks ago, when people feared the Conficker virus was readying for attack on April 1, the spammers were hawking fake antivirus software.

And what's the latest trend? Why, swine flu spam, of course (which, by nature, makes a pun completely unavoidable, I'm afraid).

Spammers are also making use of the fast-growing social networking site Twitter, which saw its popularity soar even higher after celebrities Ashton Kutcher and Oprah joined the flock a couple of weeks ago.

On Twitter, Swine Flu and #swineflu were the top two trending topics on Monday afternoon.

So perhaps it's not too surprising that the security firm Websense reported Monday that it had detected tens of thousands of spam messages marked with the "#swineflu" topic on Twitter. [CORRECTION: The public relations firm representing Websense later said that it had erred in saying that spam messages were being sent on Twitter. In fact, spammers have not yet started taking advantage of Twitter, says Stephan Chenette, Websense's manager of security research.]

Of course, jumping on a new trend doesn't necessarily mean having to dump the tried and true – the messages offer cheap pharma drugs, and Websense suspects they may be used to lure people into downloading malicious code.