everything in football is remarked upon.

Within hours of his team losing the Scottish Cup semi-final to Hearts last Sunday, Neil Lennon was engaging with his followers on Twitter. Mostly, he was either disputing their view of his team's performance, or agreeing with their responses to the decisions made by Euan Norris, the referee. No other high-profile manager in the British game uses the social network site and Lennon is often engaging, as he is in real life, but the medium is not without its pitfalls.

Disagreeing with opinions, even those of your own fans, is part of the accessibility Twitter provides to its users. Yet Lennon also said that he believed the referee's penalty award against Celtic was "personal", then he retweeted a comment from a Celtic fan that read: "Or pack our bags and get out of this league that is run by crooked SFA officials". A decision made in the heat of the moment, or instinctively, remains permanent on Twitter, and Lennon might find himself having to explain his own comment to the Scottish Football Association.

Stewart Regan, the SFA chief executive, might have cause to be sheepish, though, since he took straight to Twitter to criticise Charlie Richmond's comments in a radio interview last week, remarks that irked the Scottish Senior Football Referees Association. In its intimacy – 140-character statements made directly to people, in real time – Twitter has become a social media phenomenon, and the world's most popular sport is still coming to terms with its growing relevance.

Like all forms of social networking, the content ranges from the banal to the offensive, but it is the direct interactions that Twitter provides that makes it so compelling.

Two years ago, no ordinary fans could have spoken directly to the Celtic manager only hours after a match, let alone embark on a conversation with him. Yet with that access comes responsibility, from both sides.

Players, managers and directors – Tony Fernandes, the Queen's Park Rangers owner is an enthusiastic Tweeter, even asking fans to recommend signings – have to self-censor. Casual, throwaway remarks that could be made privately to friends are broadcast to the watching world on Twitter, so gossip, team news, injury news and, often, personal views have to be avoided. Yet at the same time, abusive tweets from followers have driven many footballers, such as John Hartson, Darron Gibson, and Kevin Davies, to quit the site.

It is the power of Twitter, its sheer weight of influence, that is its strength, but also its danger to users. In the real world, it has contributed to social and political uprisings in repressed parts of the world. Football's self-importance knows no bounds, but Twitter has at least allowed the personalities of some players to seep out, in particular Rio Ferdinand and Joey Barton, whose reputation was rehabilitated by his references to philosophy, politics, art and culture, although he also left Twitter recently after generating more controversy through his posts.

The balance to be struck is between the spontaneity and access that Twitter allows, and not saying something that you might regret. Oxford City sacked striker, Lee Steele, last January for making a homophobic comment about Gareth Thomas, the former Wales rugby player, while many footballers, from Ryan Babel to Wayne Rooney, have stirred controversy with remarks made, probably without thinking them through.

"We publish information and advice on social networking," says Jack Ross, of the PFA Scotland. "It's how to protect yourself from being involved in any disciplinary problems. Players have to be aware that they're different from the average person who uses it, because what they say will be scrutinised."

Some clubs have social media policies, others rely on the manager's discretion. Lennon could never tell his players not to use Twitter, yet Simon Grayson banned the Leeds United players from using it, and Sir Alex Ferguson remains wary of something he admits he doesn't understand.

"Social media has outpaced everybody," says Pete Wood, social media account manager at Steak, the digital marketing agency. "Players need to be told what they can and can't say. As long as there's emotion and somebody can make a statement at the end of a mobile phone, there will always be social media cock-ups. But if social media got to the stage where people weren't making mistakes, it would be a much more boring place."

Twitter provides an individual experience that is communal, and breaks down barriers between footballers and their followers. It requires common sense, though, and discretion. Yet clubs will not deter players as they have also realised its influence themselves.

"Clubs need to think more in depth about what they want their fans to get from their social media," says Sean Walsh, who runs the digital-football.com blog. "Manchester City use Twitter as an entertainment channel, whereas a club like Celtic uses it as way to provide fans with live commentary and answer customer service/ticket office enquiries and complaints."

Twitter is already part of the fabric of the game, at least for the younger generation of fan and player. Used in the right way, it is a significant tool, used wrongly it can be self-defeating.