Update: The message glitch has been fixed according to Playstation UK.

https://twitter.com/AskPS_UK/status/1051844976844464129?s=19

Sources: https://www.reddit.com/r/PS4/comments/9nselm/warning_set_your_messages_to_private/

A "glitch" through messaging has been discovered and people with PS4's should set messaging to "Private" for now.

To set messaging to private:

1. Go to Settings

2. Go to Account Management

3. Go to Privacy Settings

4. Enter Password

5. Go to Personal Info > Messaging and set Messages to "No One" or "Friends" if you trust them.

The "glitch" would brick lock-up your console and forces you to factory reset it. Beware when sending messages as the cause of this is(as Playstation Uk stated) a "Heart Emoji"which the console can't see/read.

This happens just by receiving the message, then controllers stops responding and the console crashes.

Here are some fixes I read that worked for some.(this may/may not work for you as some stated)

• Rebuild Database (this one takes a lot of time depending on your save content)

1. Power off console completely.

2. Turn on console into safe mode( Press and hold power button on the PS4 until it beeps twice).

3. Pair your Dualshock controller to the PS4.

*The console will be in safe mode.

4. Choose option 5. Rebuild Database

Now the screen will go blank and this could take hours depending on the amount of saved content.

• Delete the "Message" from your Playstation App

Just like it says, just go to your Playstation App and delete the message, now keep in mind, some says this did not work for them.

Now if those above didn't work for you, you'll just have to factory reset your system.

Wow, that's a pretty horrific glitch. When my computer can't display a character, it just displays a little square by default. Why can't PS4 do that?

For something with nasty consequences like this, spread it as far as you can. Console warriors only have words to throw around, nothing compared to a bricked console.

One, I have never made a thread just to show and ignite "fanboy wars", In fact, I despise this behavior from them and I see them as pretenders and not gamers, two, I am not one to just "sit here and watch the world burn", I try what little I can to spread tips or news be it good or bad as long as I can prevent the bad and deliver the good.

Edit: Now I believe I made one or two threads that may seem the opposite of what I said, but believe me the intention is not to engage in pointless squabble but to poke fun and only out of curiosity. 

Hey, don't antagonise us. We'll commit some serious cyber terrorism.

Wouldn't want that to happen, but nothing I can do about that now, thousands of people already saw it on twitter, it's just best to hope that Sony take notice and do something about it and that more people who are aware just do what was suggested so that this doesn't happen to them too.

is it that a bit of paranoia? 

This is ironically really fanboyish of you to say. 

I believe it will be. Which is good.

Is this real or some kind of hoax. Google doesn't find any info from Sony over this while it was reported 20 hours ago already. All the repeat articles link back to that original reddit post. I smell a hoax.