It only took a scolding letter from a Senator, a class action lawsuit and a few thousand news stories, but smartphone software makers Carrier IQ finally responded to allegations of logging keystrokes and spying on users on Thursday night. The company's denying the most serious user-tracking allegations, a number of questions remain about exactly what the software does and how users can turn it off. Among them, how long has this been going on and what the heck was Carrier IQ (and its clients) thinking in the first place?

In case you haven't kept up with the controversy, Carrier IQ's software is deeply embedded in the software of about 150 million smartphones around the world, including Android, iPhone, BlackBerry and other devices. It logs a large amount of data, the company says in an updated press release, "to monitor and analyze the performance of [mobile operators'] services and mobile devices to ensure the system (network and handsets) works to optimal efficiency." Carrier IQ describes itself as "the consumer advocate to the mobile operator, explaining what works and what does not work." But over the past couple of months, escalating concerns from data security experts and hackers alike have questioned whether or not Carrier IQ is actually overdoing it, collecting so much data that it may be violating federal wiretapping laws. On Wednesday, Senator Al Franken raised this concern in a (very detailed) letter he sent to Carrier IQ's CEO on Wednesday, commenting how recent revelations about Carrier IQ's tracking practices were "deeply troubling." On Thursday, a group of angry consumers sued Carrier IQ as well as device manufacturers HTC and Samsung for violating the Federal Wiretap Act, demanding hundreds of millions of dollars in damages -- $100 per violation per day. Meanwhile, a collective protest against the company's tracking practices is gaining steam. Not even Carrier IQ headquarters' listing on Google Places is safe from scorn. ("Did I agree to be wiretapped? Hmmmm... let me think... HELL NO!" reads one review.)

As the mounting class action lawsuit would suggest, Carrier IQ's clients -- both device manufacturers and mobile carriers -- are distancing themselves from the backlash. Apple said in a statement that it "stopped supporting CarrierIQ with iOS 5 in most of our products and will remove it completely in a future software update." Both Samsung and HTC passed the buck, claiming that mobile carriers like AT&T, Sprint and Verizon should shoulder the blame for installing the software. "Carrier IQ is required on devices by a number of U.S carriers so if consumers or media have any questions about the practices relating to, or data collected by, Carrier IQ we'd advise them to contact their carrier," HTC said in a statement. Verizon denied using the software. AT&T admitted to using it "to improve wireless network and service performance," and Sprint similarly said it only collected "enough information to understand the customer experience with devices on our network." The Huffington Post made a slideshow of all the various denials.

Like many of the great digital privacy scandals of our age, this all started with social media. Security researcher and Android developer Trevor Eckhart scared the hell out of everyone earlier this week when he posted a 17-minute-long YouTube video detailing how much data Carrier IQ actually collected, showing how it logged every keystroke, tracked your encrypted Google searches and even recorded the contents of your text messages. The company flat-out denies that last bit and "vigorously disagrees" with allegations that its software violates federal wiretapping laws. From its latest press release:

While a few individuals have identified that there is a great deal of information available to the Carrier IQ software inside the handset, our software does not record, store or transmit the contents of SMS messages, email, photographs, audio or video. For example, we understand whether an SMS was sent accurately, but do not record or transmit the content of the SMS. We know which applications are draining your battery, but do not capture the screen.

As paidContent's Ingrid Lunden and Tom Krazit point out, this response leaves a lot of unanswered questions. "Is that the full list, or is there more?" they wonder. How long does the company store the data? What about the encrypted search data? When does Carrier IQ send information to carriers? And why, oh why, can't the user simply opt-out of the service? As Eckhart made clear in his video and corresponding blog post, it takes an advanced mobile developer to find the Carrier IQ software deeply embedded in the phone's firmware.

Which brings us to the big question: how do you get rid of it? Android users are in luck. A quick fix is the brand-spanking new, unapologetically named "Voodoo Carrier IQ detector," but since it can't remove the software, it's not really a complete fix. For that we turn back to Eckhart, who wrote a Logging Test app (currently in its seventh revision) that you can download and run to find out exactly what's going on with your phone. Run the "CIQ Checks" once installed to see if you have Carrier IQ installed. If it is, you can pay $1 to upgrade to the Pro version of Eckhart's software which will remove Carrier IQ from your phone. Folks with Apple, BlackBerry and other devices are less lucky as we haven't identified an equivalent app-based solution, but TechCrunch has some good tips on what to do

We have to raise a cynical question here. Based on the stats in the Android app store, the sales of Echkart's Andoird App have skyrocketed since this scandal blew up. Diagnostic software is also pretty standard across the software industry, but given how little everyone seems to know about how Carrier IQ specifically works -- how much data it collects, who it sends it to, which privacy policy applies, how to opt out, etc. etc. -- it would appear that a little bit of oversight is in order. But it's a little shady that Eckhart's whistleblower video has turned into a source of income. It will take some more time to learn the full truth behind Carrier IQ, and we wouldn't be surprised if Franken's inquiry turns into a full scale investigation. Until then, you might want to use a landline.