Nude and explicit photographs have become more common on Twitter, and while the site began to gain momentum for marketing and customer service departments looking to promote products and services, or connect with customers, it has taken a bit of a dark turn into the world of spam, pornography and escort services.

Needless to say, marketers relying on the service to promote family values-tied goods and service don't seem too thrilled by the topless photo of Mcdowell407 and the accompanying tweet that talks about how badly one boyfriend treats her (and explicitly about what she'd like you to do to her). Nor do they appreciate half-dressed woman in bra, garters, stockings and stilettos who promote escort services, such as Taylor, by clicking on the "follow" tag. Twitter did not respond to requests for comment.

WeeWorld recently launched a page on Twitter to promote the virtual world, which caters to tweens and teens. Messages range from alerting the 3,893 followers that they can earn 50 bonus points for all WeeWorld Facebook fans, to events in WeeWorld paying tribute to Michael Jackson. If they don't do something to clean up the site, Lauren Bigelow, WeeWorld GM of North America and SVP of marketing, says the virtual world might consider pulling the page if nothing is done to clean up the site.

MerchantCircle has begun to offer a portfolio of local city specific coupons via Twitter feeds. "As we have found with any new communication form, pornography and other types of issues creep in," says Ben Smith, Merchant Circle CEO. "The problem with this type of activity is that it undermines the trust in the communication channel, which will have a disastrous effect on the channel."

Twitterers have also become annoyed. @ncwinters tweets about the "annoying strong increase in porn spam traffic" on Twitter. And, @HyacynthW, who has a blog, "The Scoop on Poop and Other Mama Dramas," tweets "What the heck? Porn messages on Twitter? I'm so not down."

Paul Verna, senior analyst at eMarketer, believes Twitter will need to find a way to filter out adult content because marketers will feel uncomfortable having their products and services, or advertising and marketing materials, serving up alongside, or anywhere near it. "If Twitter builds an advertising supported model, they will need to develop a way to isolate the content," he says. "YouTube did. Facebook did it. They had to be tough cops when it came to the content. On one hand they try to provide an open platform, but on the other if they don't set limits it could backfire."

Verna says getting a handle on the spam and the sexually explicit material another thing Twitter must fix, along with the ability to authenticate celebrity accounts, something they have stumbled with during the last few months.

While policing began with the Twitter community, Amichai Shulman, CTO at Imperva, an online security company based in Israel and Redwood Shores, Calif., believes the microblogging site could do more to filter the content. "The information from the feeds is either based on IP addresses or links, and there are services on the Internet that track and send notifications about known distributors of offending material," he says. "It would be simple for Twitter to interface with one of those services providers to filter out at least 90% of that content."

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