People used to dream about robot secretaries. Futurists imagined a world where computers obeyed our every command. When the Amazon Echo hit the market, that dream became a reality: Alexa was obedient, personable and all-knowing. She could carry out a myriad of basic tasks, with a personality as professional and unflappable as a human assistant.

This year, Echo is more popular than ever, and despite competition from Google, Amazon still dominates 75 percent of the virtual assistant market. With its ever-growing library of skills, Echo becomes more useful with every passing day.

Related: Not sure which virtual assistant to buy? Click here to find out which is best.

But even as Echo wins over more fans, critics are still skeptical. Alexa is always listening. Our voices are recorded and stored. Owners worry that their Echo will be hacked, enabling strangers to hear their daily activities. Most people are willing to ignore these dangers, but some folks who find an Echo in their stocking are terrified of an ad hoc wiretap sitting in their living room.

If you already have an Echo, be prepared for a shock. My Echo recorded much more than I ever thought was possible. Click here to learn how to hear all your Amazon Echo recordings (and delete them, too).

Before you welcome Alexa into your life, consider some security settings. You may not feel they’re necessary, but it’s good to know your options.

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1. Turn off your Echo's mic

The most vulnerable part of any Echo unit is its microphone, which absorbs all the sound in the room and may compromise your private conversations if it picks up the wrong words. To turn the mic off, press the microphone off/on button on the top. When the button is red, the mic is off. To reactivate it, just press the button again.

Then again, muting the mic will stop the Echo from hearing commands, rendering the device useless as a personal assistant. The always-on, always-listening nature of these smart virtual assistant speakers is what makes them truly compelling gadgets to have. Related: Click here for a list of Alexa commands you should be using.

Sometimes, you may wish to switch off the mic for short periods, just for peace of mind. If you’re hosting a top-secret conversation in your home, you can switch Alexa off during the sensitive parts, then reactivate her later.

2. Turn off Voice Purchasing or set up a PIN code for purchases

“Alexa, buy more laundry detergent.” This is a pretty nifty trick, and it’s a major draw for people who like to shop for household items online. This may feel like one of its most futuristic features, but a single security breach could cost you dearly.

Personally, I’ve turned off my Echo's Voice Purchasing option and use Amazon's app or website to shop. To turn it off, open your Alexa app and tap Settings. Then scroll down, tap Voice Purchasing and toggle "Purchase by voice" to Off.

Related: Click here for a list of other unexpected Alexa abilities.

If you still want the convenience (and the sci-fi vibe) of Echo voice purchasing, set up a PIN code to avoid unauthorized purchases. To set it up, go to the same Voice Purchasing settings page on your Alexa app, toggle "Purchase by Voice" to On, then toggle "Voice Code" to On as well. This will prompt you to enter your four-digit PIN code.

Now, the four-digit code has to be spoken out to complete a purchase on your Echo. That said, anyone can simply listen in and reuse your code, so having a Voice Purchasing PIN is not foolproof.

3. Check your ‘Drop In’ settings

Back in June, Amazon introduced a new Echo feature called "Drop In" that works on all Echo gadgets, including the Dot and the Show. Drop In lets other Echos automatically connect to another Echo to start a conversation. The other party doesn't even have to pick the call; the line is automatically open and works just like an intercom system.

Although convenient in some ways, this can be a privacy issue, since people can "drop in" to your Echo and listen anytime. This is why it's vital that you check your Echo's Drop In settings.

Open your Alexa smartphone app and tap Settings. Under Devices, select the Echo speaker you want to modify. Scroll down and tap "Drop In," and from here you can set it to On, Only My Household or Off.

You can set specific contacts to be able to drop in on you automatically by going to the Conversations tab (it looks like a text bubble icon) on your Alexa app and tapping the Contact icon (it's shaped like a person) in the top right corner. Based on your phone's contact list, the Alexa app will then list everyone who has an Echo

linked to their phone number (creepy, I know), and you simply toggle "Contact can Drop In Anytime" to On.

Beware that turning this on means that the contact can access your Echo devices automatically and drop in or listen and talk to them at any time.

To audit the contacts that are allowed to Drop In, go to the Contacts Menu again and check "Others Who Can Drop In on my Devices" to see everyone who is permitted. Simply tap Remove to revoke the contact's Drop In permissions.

Bonus: Switch off the Echo Show camera

If you haven’t seen it, the Echo Show is a mini-interactive TV screen with additional touchscreen controls. Selling for under $200, Show includes everything you loved about your speaker, plus transcribed song lyrics, surveillance footage of the baby’s room and video calls.

Video calls are an exciting tool, but many people find the camera to be as anxiety-inducing as the microphones. What does the camera see? Is it watching all day and night? How do you know if it’s been hacked? Many people put tape over the webcams on their laptops; they may feel compelled to do the same with their Echo Shows.

Luckily, the device’s camera and mics are very easy to turn off. There’s a button on the top of the Show that controls inputs. Just press it “off,” and both cameras and mics shut off. The front LED will also turn red, signifying that the inputs have been successfully shut down. You can still use the touch screen without a hitch.

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Copyright 2017, WestStar Multimedia Entertainment. All rights reserved.

Learn about all the latest technology on the Kim Komando Show, the nation's largest weekend radio talk show. Kim takes calls and dispenses advice on today's digital lifestyle, from smartphones and tablets to online privacy and data hacks. For her daily tips, free newsletters and more, visit her website at Komando.com.