Stop unwanted calls and texts from hitting your cellphone

File photo - Apple iPhone 6 (REUTERS/Mike Segar).

You may find this surprising. Many of us remember when people’s names, addresses and phone numbers were listed in the telephone book and distributed for free. All we ever worried about were junk mail, telemarketers and the occasional prank call.

Times have changed. Phone books are history, and your phone number has become a gateway to your primary means of communication, entertainment and safety. Once your number is compromised, it’s far more intrusive than ever before.

Spam texts and robocalls

Every year or so, a hoax warning that all cellphone numbers are about to go public burns like a wildfire through inboxes and social networks. It also says there's a deadline to register your cellphone number and that, once you register, it blocks your number for only five years.

Oddly enough, the only thing the hoax message gets right is the number to call. For the record, mobile telephone numbers have never been in any danger of being made public or released to telemarketers; there has never been a deadline to register your cellphone; and you don't need to renew every five years (this was a rule for landlines that was axed in 2007).

If you get an unsolicited marketing call on your cellphone, ask the caller how he got your number and tell him firmly you don't want to be contacted again. If he calls back, file a complaint with the FTC at donotcall.gov or 1-888-382-1222.

But these days, many companies find it cheaper, easier and more profitable to send advertisements by text.

You may also receive a host of “robocalls,” recorded messages that automatically play when you pick up. With so many cellphone numbers being collected in databases, companies have a massive list of potential customers.

Remember that texts, robocalls and telemarketers may just as likely be scammers in disguise. Use extreme caution when answering these messages, and never give away personal data. Click here to learn how to stop telemarketing calls for good.

Better yet, you can install apps on your phone that keep annoying telemarketers off your line. Click here for three apps that protect you from tele-predators.

People know it is you calling when your caller ID pops up on their phone, but it doesn’t have to be like that. There are two ways to keep your identity secret while making a call. One is permanent, and the other is temporary on a call-by-call basis. Here’s a tip that covers both methods.

Check your apps

When you receive an unwanted solicitation by phone, you may wonder: How did they get my number? I’ve given it only to friends. I haven’t posted it on social media. I barely use it to make calls anymore. What gives?

People often hand over their numbers without even realizing it. When you install an app, you receive a lengthy “terms of service” document that often contains a clause, buried in fine print, about releasing your number to third parties. By accepting these terms of service, you typically give the company permission to use or sell your cellphone number.

For example, PrivacyGrade looked at the Brightest LED Flashlight app and found it can read the phone’s current state information, including phone signal, carrier, device ID and phone number. Before you install an app, take a moment to learn exactly what information it is collecting and how the developers intend to use the data.

Fortunately, most of the heavy lifting has been done for you. Click here to learn more about how PrivacyGrade shows you an A+ to D rating on any given app's permissions.

Social media and phone numbers

Many people are careless on Facebook and give criminals heaps of personal information without a second thought. They post their birthdays and home addresses, and they even indicate when they’re home or away.

Putting your cellphone number on social media can be hazardous, especially if you have a lot of “friends” you don’t know in real life. You may have tight privacy settings, but if you agree to be friends with a stranger, your data could easily be copied-and-pasted into nefarious hands.

You may find it easy to find volunteers for your upcoming benefit by posting your cell number on Twitter, or you may take a picture of your “Missing Dog” sign and post it on Instagram … but put on your thinking cap. The short-term benefits aren’t worth the potential data breach.

Phone numbers and security verification

Password? Check. Secret security question? Check. Phone number?

More and more, secure websites are using your phone number to verify your identity. If you have an Amazon, Facebook, Google, Microsoft or Apple account, give them your cellphone number in your security settings. This way, if someone signs into your account using a new device or location, you receive an immediate alert.

You can also receive an alert if someone tries to change your password. If hackers steal your password and try to log in to your account on an unknown computer, the site will ask them for the second code. Unless they also stole your phone and were able to unlock it, they will not have the second code needed to log in.

It’s called two-factor authentication, and it’s an important safety measure. If you haven’t set it up yet, don’t wait for something bad to happen. Click here to learn how to secure your online accounts now.

Are you starting to wonder what other kinds of data you’re sharing without realizing it? I cover this topic regularly on my national radio show. Be sure to listen or download my podcasts, or click here to find it on your local radio station. You can listen to the Kim Komando Show on your phone, tablet or computer. From buying advice to digital life issues, click here for my free podcasts.

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