Amazon has added new weapons to its arsenal as it tries to take on Apple in the tablet computer war. Several new versions of its Kindle Fire tablet were announced yesterday as the company gears up for holiday shopping season. Plus, it’s the last show from John Moe, Larissa Anderson and Marc Sanchez. They look back at their favorite Tech Report moments.

Here’s what we know: There’s been a hack that involved information about at least 12 million Apple devices being posted online. It’s been in the news and it sounds kind of scary, especially because if you have an iPhone or an iPad, data about that gadget could be involved. First thing: Don’t freak out. Second: Keep changing your passwords.

Apple has announced an event for next Tuesday. It’s expected to debut a new iPhone. Apple fanatics will go bonkers, count on it. But another phone shows up today: Nokia’s new Windows Phone. You won’t see long lines to buy it. Windows Phones are a dud, making up less than 3 percent of the market, which is weird when you think of how ubiquitous Windows is on computers. So what problems are the phones are facing?

Are we prepared for a world where people print guns? We better be; Advances in 3D printing have led to difficult issues for law and government. In this episode we talk with Jonathan Zittrain, a law and computer science professor at Harvard and co-founder of the Berkman Center for Internet. He explains how 3D-printing technology is being used to make guns and gun parts, and explores how the do-it-yourself gun industry might be regulated in the future.

In honor of Labor Day, we have the story of one of the hardest working symbols around; the @ sign, that we use when we email and when we tweet. William Allman is the author of “The Accidental History of the @ Symbol,” in this month’s Smithsonian magazine. He offers some interesting tidbits on the @ symbol.

Computer security experts are ringing alarms about Java. Nope. Not the coffee. Java the piece of software that you probably have on your computer. Turns out, Java has some pretty major security flaws that hackers can and are exploiting. Plus, we take a look at the future at the IFA trade show, a consumer electronics show in Berlin going on now.

So just how much privacy can you expect for your Twitter account? That’s the question in an ongoing New York lawsuit involving an Occupy Wall Street activist named Malcolm Harris. He was charged with disorderly conduct. Prosecutors want access to his tweets. This week, Twitter appealed a ruling that it had to hand them over. So where do privacy rights begin and end with social networking sites like Twitter?

Know how you have to turn off your Kindle when you’re on a plane, at least when you take off and land? The FAA is asking for public comment on those rules. There are two ways digital devices cause problems — one through radio frequency and one through Wi-Fi frequency. Is one worse than the other? Are either harmful?

There’s a flood of new smartphones and tablets coming on the market. Microsoft, Amazon, Nokia, Samsung and Apple are all reportedly gearing up for fall releases. Part of deciding which one to buy is about who has the better apps. Turns out Apple’s patent win over Samsung could affect the answer to that question — especially for Android app developers.