06/10/2011 06:56 pm ET | Updated Aug 10, 2011

What Anthony Weiner Didn't Say On Twitter Also Got Him Into Trouble

It wasn't just what Congressman Anthony Weiner tweeted that got him in trouble: It was also whose tweets he read.

The New York Democrat's sexting scandal came to light after he accidentally posted a lewd photograph of his crotch on Twitter, setting off a bungled cover-up attempt, then a tearful apology and revelations of even more extensive and x-rated electronic sexcapades.

Weiner, an avid Twitter user whom The New York Times described as a "technophile," made his first social media mistake when a Twitter typo turned a private message into a public post. But even before, he was asking for trouble by following other Twitterers that hinted at his extramarital interests.

Even if you're not engaging in illicit activities or a public figure trying to keep his personal life under wraps, Weinergate reveals just how many digital footprints we leave on services like Twitter.

Weiner's experience serves as a warning about the numerous ways online activities can expose personal information. A Twitterer need not hit send to let secrets slip: A user can be judged not only on what he tweets, but also on the digital relationships he forms online.

Months before Weinergate erupted, a self-described conservative group started tracking what users Weiner had chosen to follow on Twitter and made a discovery: The congressman appeared to have a predilection for following young women. The group, which used the hashtag #bornfreecrew, cautioned some of the women to be wary of Weiner, among them Gennette Cordova, the Washington co-ed to whom he later tweeted the image of his underwear.

The crew, "closely monitored those whom Mr. Weiner was following, taking it upon themselves to contact young women they believed to be 'schoolgirls,' and urging them publicly to stay away from him, according to an analysis of posts on Twitter's public stream,” wrote The New York Times. "By early May, members of the group were also speculating that Mr. Weiner would be caught in a sex scandal."

Horror stories about people that have been fired or even arrested over tweets, Facebook photos, and YouTube videos have made people cautious about what they share with the web. Yet most overlook the danger that their online acquaintances may reveal more than they realize about their interests, political affiliations, religious beliefs and sexual orientation.

The social connections people have curated on online profiles can expose a great deal about their lifestyles. For example, researchers at MIT found that they could predict whether a person was gay by analyzing their Facebook friends.

"People understand that what they tweet or post on Facebook will be there forever, so they should be careful," said Murat Kantarcioglu, an assistant professor of computer science at the University of Texas. "But I don't think they've gotten to the next level yet... Following people suggests you have a relationship with that person. It surfaces your connection with them.”

Weiner is not the first public figure to come under scrutiny for his Twitter timeline, nor is he likely to be the last.

When Eric Schmidt, then CEO of Google, first joined Twitter, the people he initially followed on raised eyebrows as they included reality TV celebutante Heidi Montag, notorious for her extensive plastic surgery procedures.

The 96 people Schmidt currently follows on Twitter are a surprising mix of Hollywood stars and Silicon Valley luminaries, suggesting the executive may have some less obvious interests outside of search engines and smartphones. In addition to fellow Googlers, such as Marissa Mayer and Vic Gundotra, Schmidt also follows rapper Kanye West, singer Akon, Australian model Ceyenne Tozzie and twenty-something pop singer Matisse. He also follows virtual unknowns such as (@PersianNathalie, who recently tweeted, "60 yr old chauffeur asked me to roll down my window at light to tell me I had beautiful hair and he'd like the run his fingers in it!!"), and Alex Smith, whose bio reads, "When it's all for love, it's love for all :)." Schmidt's announcements at board meetings and press conferences have offered few hints that he may have an interest in rap music or modeling.

Users can do little to disguise whose tweets populate their timelines. It is built for public discourse, not private conversation, and essentially all activity on the social network is visible to everyone else.

Whereas Facebook allows users far more granular control over the information so that they can specify that different data will be visible to different groups -- whether classmates, relatives, or employers -- Twitter has just one privacy on/off switch. Either your profile is public, and every tweet you send, every account you follow, and every account that follows you is visible to anyone on the Internet, or your profile is "protected," meaning that people must receive your permission before they can access your account. Once you have approved them, they can see every tweet you send, every account you follow, and every account that follows you.

In other words, Twitter is an all-or-none platform that assumes users are comfortable being transparent about their content and their contacts.

"Even though people complain about Facebook privacy all the time, there is a greater level of privacy. On Twitter, it's always public," said Graham Cluley a security expert at Sophos, an antivirus software vendor. "On Twitter, the default is to have everything open."

Though users have the option to make their tweets private, doing so makes it more difficult for them to gain followers and broadcast their message, ultimately hindering Twitter's usefulness. Tweets from a protected account cannot be retweeted by other users, or viewed by people that have not been approved, which limits the exposure these posts will receive.

"The only way to protect yourself is to make your profile completely private. The vast majority don't do that on Twitter because that won't work well if you want to grow your userbase," said Cluley. "You can't use Twitter with any sort of power or strength to get your message out if you have a closed private profile. You have to be open to use Twitter. It's essentially used now to broadcast information and gain more followers."

Short of quitting Twitter, users wary of what their relationships may reveal should consider carefully curating whom they follow. But having very few users can also call attention to outliers -- the porn stars, the cute co-eds, the models -- and some experts say that following tens of thousands of users, while potentially producing an overwhelming number of tweets, could be a defense against anyone reading too much into your Twitter choices.

"If you have connections you want to be protective about, hide the needle in the haystack," said Kantarcioglu.

Alternately, users could abide by Schmidt's own advice to people worried about their privacy online. "If you have something that you don't want anyone to know, maybe you shouldn't be doing it in the first place," he has said.

Cluley added, "The other thing you can do is think with your head, not with your trousers."

Has the Weiner scandal changed how you use, check or post to Twitter? How? Let us know by emailing technology [at]