Twitter becomes more and more a vector for marketing and less and less a path for valuable (or even just fun) information. If Twitter can't find away to curb this use of their system, they're leaving themselves wide open to be replaced by some other simple tool.
To combat almost ubiquitous "reply spam", many of us have closed our Twitter accounts so that our tweets are not public. By keeping them out of the public timeline, we don't get reply spam most of the time. It reduced the value of Twitter, however, as the general public timeline will decline in value more and more as people do this.
Since so many "prime targets" for spam are no longer reached this way, there are two growing trends that we're seeing more and more of. The first is Twitter handle lists. Spammers now trade, sell, and maintain lists of twitter handles so that you be "mention spammed" even when you don't tweet and even when your posts are protected. The spammers know that most people get notified when someone mentions them even if they don't follow that person -- often with email notifications or cell phone alerts -- so it works perfectly for spammers. So....now we close that down by not allowing notifications from people we don't follow or people we haven't allowed to follow us. Another value drop for Twitter.
Now the newest one I'm seeing a big uptick in. Since you can't see my twitter posts unless you follow me, but you know that if you request to follow me I'm going to see that request; spammers and "social media consulting" companies (as bad as SEO people, in my book) have companies set up a company twitter account where the "quick description" is itself a little ad for their product. Then they run scripts to request to follow huge numbers of people. As a result, we get email saying "@Someone has requested to follow-you" and right there in that email is the advertisement disguised as the one-liner about them. The goal is to get you to first, read that ad (done) then possibly to get you "allow" them to see your timeline -- now you're subject to their "reply" spam, and finally they hope you "follow them back" (which used to be a common practice).
Stopping this stuff is going to take some creativity. Preventing any accounts from making more than "N" requests to follow in any 24 hour period would be a good start. Preventing accounts less than "N" days old from some activities would help a great deal. Giving us tools to now get ANY notifications from accounts less than 30 days old would really help a lot as well.
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