(Credit: Bruno Cantuária)

"Hello. Would you like to stop robocalls?"

Why does it seem like the only people who call anymore are the robots? Because maybe it's true. Federal Trade Commission (or FTC) reports robocalls are on the rise, in part because it's so easy to make autodialer calls from anywhere in the world. When a colleague said he was receiving 20 robocalls *a day* on his mobile phone, we looked into what he could do to stamp out the annoying mobile calls.

So what is a robocall? A robocall is a call to your landline or mobile phone that uses an autodialer to send a recorded message and then connect you to a live telemarketer. While federal and state governments have attempted to restrict these telemarketing calls, robocalls can use a variety of tactics, including Caller-ID spoofing, to hide their location and evade detection.

What can you do? The simplest thing is to not answer a call from an unknown number. If, however, you do answer a robocall, the FTC recommends you hang up and do not press a number, as pressing any number will likely flag your phone number for more robocalls. The FTC also recommends you register your home and mobile phone numbers with the National Do Not Call Registry. While some types of calls -- such as from charities or political groups -- are allowed, being on the do-not-call list should cut down on unwanted sales calls at least. And after signing up, you can report unwanted calls to the FTC.

What else can you do about robocalls? On your iPhone or Android phone, you can try installing an app to identify and block unwanted calls. The apps all take a similar approach: checking incoming calls against a robocall database. The apps block calls only from known robocallers, however, so fresh unreported numbers may still get through to you. Or, you can strike back with the Jolly Roger Telephone Co. Through the service, you can pass telemarketers to Jolly Roger bots that attempt to keep the telemarketers tied up with automated responses. Check out the company's blog to hear recordings of the bots in action.

If you are on an Android phone, the phone app may include a robocall filter to help you block robocalls. In your phone's setting you can turn caller ID and spam protection on and then can see information about a caller who is not in your contacts or a warning about a potential spam caller when you get a suspicious call.

SEE: Stay private and protected with the best Firefox security extensions

1. TrueCaller

TrueCaller's Caller-ID service (Android and iOS) attempts to match an incoming caller's number with a name in the company's database. TrueCaller users can add spammy numbers to the community-build database, and you can look up numbers as well as share contact information with other users. The free version is supported by ads. A $17.99 annual subscription removes the ads.

(Credit: TrueCaller)

2. Mr. Number

Mr. Number (Android and iOS), from Hiya, lets you assemble lists of numbers to block calls and SMS messages. You can take a more active roll with Mr. Number, deciding whether to pick up, hang up, or send a caller to voicemail. The app is free, and in-app purchases start at 99 cents.

(Credit: Mr. Number)

3. Nomorobo

Nomorobo (Android and iOS) takes an active approach and monitors incoming calls. If the call is coming from a trusted number, it lets it go through. If it's from a robocaller, it intercepts the call and hangs up for you. Subscribe for $1.99 a month.

(Credit: Nomorobo)

4. YouMail

YouMail (Android and iOS) offers much more than robocall blocking. It can assist with setting up phone conferences, converting voicemail to email, and responding to incoming calls. And, of course, it can block calls from blacklisted numbers, sending them directly to a message stating your number is out of service.

(Credit: YouMail)

5. RoboKiller

RoboKiller (Android and iOS) doesn't just block all these calls; it actually answers them with answer bots, which are robots of our own that talk back to the spammers and waste their time," RoboKiller is free to download and costs $3 a month, but you can try it free for seven days.

(Credit: RoboKiller)

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Clifford is an Associate Managing Editor for CNET's He spent a handful of years at Peachpit Press, editing books on everything from the first iPhone to Python. He also worked at a handful of now-dead computer magazines, including MacWEEK and MacUser. Unrelated, he sits next to fellow editor Josh Rotter and roots for the A's.