Cristiano Ronaldo is unquestionably one of the greatest footballers in history.
What Ronaldo has achieved is simply astonishing and it's why he has millions (if not billions) of supporters around the world.
However, just because the 36-year-old is an all-time great and hugely popular doesn't mean he's completely immune to criticism.
There are quite a few who still pick fault with the United man's game, one of the most prominent being Antonio Cassano.
The Italian icon said in the past that he doesn't think Ronaldo is one of the top five players ever, ranking Lionel Messi, Pele, Diego Maradona, Johan Cruyff and Brazilian Ronaldo ahead of him.
Cassano has also previously claimed that the five-time Ballon d'Or winner is 'selfish' and it seems Ronaldo is very unhappy with the criticism aimed at him from the former Inter Milan and Roma striker.
In fact, the Portugal international was allegedly so upset at one point that he actually sent Cassano an 'angry' text in response.
Cassano said on Christian Vieri's Twitch channel, per Daily Record: "Ronaldo wrote me messages! Cristiano Ronaldo, telling me that I need to have respect for him because of the trophies he's won and the goals he's scored.
"I'm not afraid to tell the truth, I'll face anyone from the Pope to the last on this earth.
"I called Buffon and he confirmed that he gave my number to the press officer, who turned it over to Ronaldo so he could tell me he's scored 750 goals and I only got 150.
"To him I'd just say: dear Cristiano, you have everything. Be calm and relaxed. Take your example from Messi, he doesn't give a damn about anything or anyone.
"He sent me a message, honestly it's the truth. Gigi Buffon knows it well, Gigi laughed about it. Chiellini knows too.
"It made me angry: what are you doing? What is your problem?"
So, if you're a high-profile figure and you criticise Ronaldo, be prepared for a fiery text message from an unsaved number...