• by Wendy Davis , Staff Writer @wendyndavis, November 26, 2014

In the latest data grab by a Silicon Valley company, Twitter said today that it will start collecting information about which other apps are installed on its users' phones.

The company says it is doing so in order to “build a more personal Twitter experience” and “deliver tailored content” -- both of which are odd justifications, considering that Twitter users already personalize their experiences by deciding which other users to follow.

The company obviously hopes the move will boost its ad revenue. And there's reason to think that it could -- especially if Twitters' users have apps from ecommerce sites installed on their phones.

But the problem with Twitter's decision is that the company will collect this data without asking first. Instead, Twitter will let people opt out of the new “app graph” feature. (Also, if people have used their mobile phone's privacy settings to limit ad tracking (on Apple devices) or opt out of interest-based ads (on Androids), Twitter won't collect the names of apps.

In the past, Twitter has drawn praise from privacy watchdogs. The company is one of the few to honor browser-based do-not-track headers; it doesn't collect Tweet button data from users who have turned on do-not-track. Twitter also has gone to court to challenge subpoenas for information about its users.

But today's news is raising eyebrows. Marc Rotenberg, president of the Electronic Privacy Information Center, said Twitter's move “shows the failure of the opt-out model.”

“Few users will be aware of the changes and even fewer will have provided meaningful consent for Twitter’s new data collection practices,” he says in an email to MediaPost.