London - Premier League stars have been warned not to step out of line on Twitter as the English Football Association responded to a spate on controversies involving the micro-blogging website.
Liverpool's Ryan Babel became the first player to be sanctioned for comments made on Twitter last month when he was fined £10 000 for posting a mocked-up picture of referee Howard Webb wearing a Manchester United shirt.
Arsenal's Jack Wilshere also drew criticism after he complained of "inconsistent refereeing" on his Twitter account following the Gunners' stormy 4-4 draw at Newcastle.
Wilshere escaped punishment for that incident but the FA have now made their hardline policy clear.
An FA statement read: "The FA has issued clarification to participants relating to the use of social networking sites, including, but not limited to Twitter, Facebook and internet blogs.
"Participants should be aware that comments made on such sites may be considered public comment, and that further to FA Rule E3, any comments which are deemed improper, bring the game into disrepute, or are threatening, abusive, indecent or insulting may lead to disciplinary action.
"Comments which are personal in nature or could be construed as offensive, use foul language or contain direct or indirect threats aimed at other participants are likely to be considered improper."
Players have also been warned that even though they believe their postings are only visible to a limited number of selected people they may still end up in the public domain.
"Consequently, care should be exercised with regards to the contents of such postings," says the statement.
"In addition, we would remind participants that social networking postings could also lead to civil proceedings being brought by affected parties."