Two Major Forms of Phone Spams
Telephone spam describes unsolicited messages sent to phone users, typically for advertising purposes. They are usually an unwanted form of communication distributed in bulk and without prior requests by the recipients. Telephone spam may come as phone calls and text messages. They are usually also used in phone scams.
Phone spams typically take on one of two forms: spam calls and spam messages. Spam calls are phone calls sent to a large number of receivers without their consent. Spam calls are typically disseminated as robocalls to the recipients, none of which expressed interest in receiving these calls. On the other hand, spam messaging, also known as SMS spam, refers to unsolicited text messages sent to mobile phones.
Phone spam is traditionally used for commercial advertising purposes, non-commercial proselytizing, and public service announcements. However, it has also been abused for malicious and fraudulent purposes.
Is Phone Spam Legal?
The Telephone Consumer Protection Act of 1991 restricts telephone solicitations and limits the use of automated telephone equipment for these purposes. This equipment includes auto-dialing systems, artificial and prerecorded voice messages, SMS texts, and faxes. It also spells out several technical requirements for the use of these types of equipment in contacting consumers.
Federal law asserts that it is illegal to send unsolicited commercial text messages to wireless devices without the device owners’ explicit permission.
What is VoIP Spam?
VoIP spam uses Voice over Internet Protocol technologies to deliver unsolicited, auto-dialed telephone calls colloquially referred to as SPIT. SPIT (Spam over Internet Technology) broadcasts unsolicited bulk messages to phones connected to the internet using VoIP technologies. This is a more efficient means of making calls because the senders can send messages in bulk instead of dialing each number separately. Spammers use VoIP systems to initiate voice sessions and make unsolicited phone calls that play recorded messages when answered.
To mitigate SPIT, a robust caller identification system is required to differentiate real calls from spam calls. Because regular Caller IDs can be easily spoofed, it might not suffice for this purpose. Various frameworks have been proposed, and due to the real-time nature of phone calls, solutions used for email spam detection are not directly applicable.
Proposals for SPIT mitigations focus on callers’ reputations and behaviors and machine learning classifiers using features extracted from call data. Another approach uses identification techniques to detect calls with identical caller audio data.
Overall there is limited information about the implementation of SPIT mitigation measures by telephone companies, though smartphone vendors incorporate spam call notifications in their devices. Some basic methods identified for mitigating telephony spam include:
- Whitelists and blacklists
- Consent-based communications
- Reputation systems
- Address obfuscation and limited-use addresses
- Turing tests, CAPTCHAs, and computational puzzles
- Legal actions
How Do You Avoid SMS Spam?
SMS spam has become widespread in today’s digital society, just like robocalls and junk emails. While not as invasive as robocalls, SMS spam is still harmful to recipients. It can be used to send malicious software (malware) to user devices that enable fraudsters to steal sensitive information. Also, depending on the mobile phone plan, there may be charges for incoming text messages increasing the recipient’s phone bill.
The following are ways of reducing SMS spam.
Do Not Respond
Refrain from responding to SMS spam and just ignore them. Most of these messages include options to inform the company to remove you from their distribution lists by texting STOP to a number. However, this action confirms that the phone number is active. While a legitimate company will honor your request, a fraudster will not. By sending a response, you may inadvertently set yourself up for a deluge of SMS spam.
Block Phone Numbers
Phone device manufacturers include features for blocking communication from specific phone numbers. Both iOS and Android have these features, and you can use them to block phone numbers sending SMS spam. The downside to this, however, is that spammers can easily spoof or switch phone numbers. So, while you may have blocked a phone number, you can still receive spam messages from the same person on a different number.
Report the Phone Numbers
Report phone numbers sending SMS spam by forwarding the original messages to your mobile phone carrier. To do this, copy the message and text it to SPAM (7726). This service is available to customers of AT&T, Verizon, T-Mobile, and Sprint. Your phone carrier will use the information to block future spam messages. You can also report the phone number to the FTC using the complaint assistant.
Set up Message Filtering
This is a process that allows device owners to filter incoming messages and separate valid text messages from spam. Filter SMS spam using features available from device manufacturers (Android and iOS) and mobile carriers. Several third-party applications exist that provide spam filters. These applications are available for free or for nominal fees.
What are Private Organizations doing to Stop Spam Calls?
Private organizations are fully invested in the fight against spam calls. These organizations include major phone carriers, telephone device manufacturers, and numerous companies offering third-party applications.
All four major phone carriers provide tools for blocking spam calls. These are
AT&T Call Protect
This application is available for Android and iOS devices. The free version of this application blocks calls from possible fraudsters and identifies telemarketing calls. It also enables users to add phone numbers to the carrier’s list of blocked numbers. The paid version provides all the above facilities in addition to Caller ID identification for unknown phone numbers.
Verizon Call Filter
The free version of this application provides spam detection, spam filters, and reporting options. The paid version offers the features mentioned and also includes Caller ID, spam lookup, and a personal block list. This app comes built-in for most Android devices and is auto-enabled on Verizon post-paid mobile plans. The app is also available from the Apple App Store for iOS devices.
T-Mobile Scam Shield
This application is a new offering from T-Mobile and comes with multiple features, including enhanced Caller ID and call blocking features to block spam calls. This app is free to all T-Mobile subscribers.
Sprint Call Screener
This application identifies and labels or blocks suspected spam calls. It also allows phone users to report spam calls. The paid version includes additional features such as call history and call-back reminders. The takeover of Sprint by T-Mobile resulted in T-Mobile making this app available for free to all customers.
Use Spam Blocking on Phone
To turn on the spam-blocking features on Android devices:
- Open your device's Phone app.
- Select More, then select Settings, and then Caller ID & spam.
- Turn on Caller ID & spam.
- Turn on Filter suspected spam calls.
Android users can also mark calls from specific numbers as spam and report the spammers. To do this
- Open the Phone app
- Go to Recent calls
- Tap the call you want to report as spam
- Tap Block/report spam. You will be asked to confirm you wish to block the number.
- Tap Report call as spam
- Tap block
You can also unblock a number if and when you so choose.
You can block phone numbers that you have had contact with and that are not saved in your contacts list on iOS devices. To silence unknown callers on iOS devices, go to Settings > Phone > Scroll down > Select Silence Unknown Callers. Calls from unknown numbers are silenced and sent to voicemail. They will also appear in your recent calls list.
Various private companies provide third-party applications to stop spam calls. These applications exist in free and paid versions and offer different levels of protection. They rely on constantly updating lists of robocallers, spammers, and fraudsters and use those databases to stop spam calls. To use these applications, download them onto your smartphone from online stores like Google Play Store and Apple App Store. Examples of these applications are TrueCaller, Nomorobo, Robokiller, and Hiya.
To enable third-party blocking apps on iOS devices
- Download the spam blocking app from the App Store
- Launch Settings from your Home screen.
- Tap Phone.
- Tap Call Blocking & Identification.
- Tap the switch next to the call-blocking app you'd like to enable.