There is an article in circulation that instructs that "When you dial the code (*#61#), it will show whether your calls or fax or data are been forwarded / monitored or not". This has been checked to be false.
Okay. So if this turns out the way this article describes, it doesn't mean that you are being monitored. What it means is that you or someone at some point has activated call forwarding on your line. They may have dialed a similar short-code or used the functionality on the phone to activate it.
*#61# is a short-code to check the status of call forwarding on your line. There is actually a manual method of doing this on most phones. Call forwarding is a service from mobile network providers, that allows you to take calls from another line if for whatever reason, your current line is not available. Simplest form of call forwarding is "activating voicemail" - calls enter voicemail based on the criteria you set. Someone might say, I didn't activate anything on my line. Network providers sometimes may set your line to forward to voicemail by default, that doesn't tanslate it to being monitored.
Call forwarding isn't a monitoring feature. No one can actually monitor your call activities with call forwarding. But it can allow your calls to be answered by another party (if the condition set is met). For instance, if you set to forward all calls, you will not receive any calls on your line, but the number you set will get all the calls.
1. Your mobile network provider
2. Anyone who can eavesdrop between your phone and the masts
3. Your phone Operating System provider (Google/Apple)
4. Apps installed on your phone that has the "phone" privilege.
So who is responsible for this viral "fake news"? Yes, there are some people who feed from sharing or publishing supposedly helpful topics to scare people or ginger them to take action.