Be careful of what you post on social media. A seemingly harmless tweet or Facebook post might make or mar you.
Sergi Guardiola, a player who was signed into Barcelona B team was sacked same day, as a matter of fact, 7 hours later following some offensive tweets he posted sometime 2013.
Three tweets were dug out by Spanish press. All translated in English.. 
1) ‘Up Real Madrid and to hell with Catalonia’
2) ‘Today to hell with Catalonia and up Real Madrid’.
3) I wouldn’t have Messi in my team – he just walks about… he spoils the way the team plays 
The club later released a statement on the issue.
“FC Barcelona has decided to terminate the contract signed with Sergi Guardiola, after finding that he had published offensive tweets about the club and Catalonia.”
 The distraught player told  Spanish radio station Cope  “I know I made a mistake. I apologise to Catalonia and Barcelona. I understand the decision, I’d do the same.
“I want to make clear I didn’t write those tweets. A friend took my phone and did it. It’s a misunderstanding.
“The tweets are from 2013, a joke from a friend, I didn’t even know the tweets existed.
“Barcelona have treated me very well. I understand their decision. Now I’m going home, we’ll see what happens.” the 24 year-old said.