The FA have taken a new hard-line stance against players who use Twitter and other social networking sites to criticise match officials.
The news comes in the same week that controversial QPR captain Joey Barton announced his return to Twitter after what he called a 'sabbatical'.
Disciplinary chiefs have warned that internet posts will now be treated as public comment, and are therefore susceptible to the same rules as if they appeared in newspapers, on radio or on TV.
The FA have sent written warnings to all licensed agents after numerous complaints against attacks on referees. Players have been told that deleting posts or claiming that their account was accessed by another are no longer acceptable defences.
Any comments about a person's ethnic origin, colour, race, nationality, faith, gender, sexual orientation or disability 'may be considered aggravated and attract a higher disciplinary sanction' warns the letter.
Even re-tweeting another person's post could lead to disciplinary action, while deleting an improper posting will not prevent action being taken.