Twitter spam is on the rise. Is your computer safe?

First, the good news: according to a new Nielsen report, the amount of time users spend on Twitter rose 3,712 percent to nearly 300 million minutes over the past year. And now, the bad: a substantial portion of that traffic could be spam. Writing today on FoxNews.com, Steven Kotler argues that the number of "unwanted tweets is rising. What was once maybe one or two messages a day has now risen to around 10 percent of everything that's showing up."

The first phase of Twitter spam, Kotler says, was easy to identify. Each tweet was a basic link or photo – and users could quickly delete the offending material. But the second phase, "is a lot harder to identify," he continues, "and thus a lot harder to protect against. By using computers to hunt for keywords and replying to 'relevant' usernames, spammers are dumping their Tweets into your 'timelines' — recent Twitter posts by yourself and everyone you're following."

Last August, Twitter's Evan Williams took to his blog to discuss "Twam," as it has come to be known:

Recently, we've seen significant impact by introducing limits around how many accounts can be followed on Twitter under certain conditions. These limits are designed to not affect the vast majority of users. However, some people (who are not spammers) have (and will) run into them.

So how should users protect against Twitter spam? In a January interview, Dave Marcus, director of security research and communication at McAfee Avert Labs, told me that, “It comes down to reading. I always read the subject line of the e-mail. In many cases, that’ll give you something – sometimes, they just look wrong.” He was referring to Facebook messages, but the warning is applicable to Twitter users are well. Take care when opening URLs – even ones that come directly from friends and family.

You can also tune into sites such as Stop Twitter Spam, which track developing viral attacks. Nothing's certain, of course, but with vigilance, you can cut down on the volume of incoming.... "Twam." There. I said it.