Who’s to blame for Twitter spam? Obama, Gaga and you

You know Twitter spammers, don’t you? The “egg” people. The sexbots that keep following you. The auto-responders that prick their ears up if you mention words like “iPad” or “mobile” and start sending you links. These pests are the biggest problem with Twitter spam, right?

Not quite.

While such accounts are a pain — and Twitter spends significant resources trying to hunt them down — a new study says that the most egregious promoters of Twitter spam could actually be the likes of Lady Gaga or President Obama … and even you.

The study, from researchers at the Max Planck Institute for Software Systems in Germany, examined more than 40,000 identified spam accounts, and looked into how they tried to achieve success.

“Pretty much everyone on Twitter is targeted by spammers,” says Krishna Gummadi, head of the networked systems research group at MPI-SWS. “But the key question for us was ‘why would someone follow a spammer?’. So rather than focus on spammers themselves, we looked at their support network — the people who helped them.”

And what they discovered was that instead of being supported by other spam accounts — as is common with web-based spam — the egg people were reliant on real Twitter users for their success.

How it works

At the heart of Twitter’s spam problem are two things: the way the social messaging service works, and the way search engines think about the site.

First, Twitter prominently displays follower counts as a crucial measurement of popularity — something Google and others use that number to help determine somebody’s authority. Then, there’s a secondary effect: if you are followed by somebody who is followed by lots of people (what the researchers term somebody’s “indegree”) then your influence increases even more.

This leads to a kind of Twitter-based link farming, where spammers don’t simply target small-time users with just a few friends, but larger accounts with thousands — or sometimes millions — of followers. And unlike the web, where people with high reputation tend not to link to nefarious, spammy sites, many Twitter users automatically follow back anyone who comes their way.

“At the high end, politicians like Barack Obama’s campaign staff, or the UK Prime Minister’s office, these guys tend to follow back because they want to increase social engagement. But they’re following spammers back,” says Gummadi.

That top tier of users is topped by Yoko Ono, who boasts more than 775,000 people on her following list, but includes Gaga (currently following 139,000 people), Britney Spears (416,331).

But perhaps more dangerously, the study found that it was those in the middle of the scale who were causing the most damage by handing spammers credibility.

“The people with very low indegrees of just a few people were not responsible for spammers,” he says. “It was really people with 1,000 to 5,000 followers who were worst — that’s the range where there are a lot of people who follow back anybody. These are the social marketers.”

It’s a well-known grey hat tactic that following more people will increase your own follower count, and many people who try to profit will inflate their figures by following as many people as they can. But those individuals who are just trying to bump up their numbers are not just hurting their clients — they’re ruining search results for the rest of us.

“They want to increase their social capital and they have very similar incentives to spammers,” says Gummadi. “Spammers want to collect links, social marketers want influence. So they end up colluding with each other, even if not intentionally.”

You ain’t no follow back girl

Having identified the most dangerous Twitter users, Gummadi’s team — which included researchers from IIT Kharagpur, India, and UFOP in Brazil — have started exploring ways to reduce the impact of indiscriminate follow-backs.

That’s complicated, because it involves trying to change people’s behavior. But the researchers suggest it may be possible to implement some sort of “collusion rank” to sift out those people who are giving spammers oxygen and demote them. Just like Google’s pagerank can change depending on a site’s behavior, so too could their Twitter ranking if they link to too many spam accounts.

The team recognizes, however, that this may be tricky — because the line between helping a spammer and trying to be a good social network user can be very, very fine. After all, imagine how much time it would take Barack Obama’s team to sift each potential follower for spamminess — and the outcry if there was some sort of incorrect line drawn.

Whatever the case, it is clear to the research team that fighting Twitter spam needs to be about more than just shutting down accounts.

“We’re only beginning to understand spam in Twitter, and we’re sketching a solution,” says Gummadi. “But it does not lie in just banning spammers, because it doesn’t stop the social marketers.”