Some £2bn is being provided by the sponsors of the 2012 London Olympics. Without substantial financial contributions from firms like Coca-Cola, McDonald's, BP and BMW it would, quite simply, not be possible for the Games to happen. So it is quite right that the London 2012 authorities should seek to control the use of official names and logos and prevent their unauthorised use by other companies. Coke would rightly object if adverts for Pepsi were emblazoned across billboards within camera shot when coverage commenced.

Having said that, the authorities should be reasonable and proportionate in how they apply the rules. It is one thing to prevent what the advertising industry calls "ambush marketing", whereby big businesses attempt to attach their image to the Games without paying sponsorship fees. But reports suggest that those in charge are being ridiculously overzealous in their interpretation of what violates the rules.

This extends from prohibiting local firms from using the words "London 2012" on their advertising to outlawing the use of images of previous Games. Brand police will have the power to force pubs to take down banners inviting the public to "Come inside and watch the Olympics on our TV". They have announced they will force roadside hotdog stands to place stickers on any products that are not official to cover up their brand names. Traders have been told they can only sell soft drinks and bottled water from the Coca-Cola corporation.

Businesses will not even be permitted to use the official logo on their website to create a link to the official Olympics website. And it is not just businesses along official Olympic routes; an entertainment company in Brighton, whose website advertised "sports-themed acts for 2012", was told one acrobat could not be photographed using hoops in the Olympic colours.

Such restrictions are absurd. They risk souring the public passion and goodwill surrounding the 2012 London Olympics. They also create unnecessary burdens for the small firms and one-man businesses which the politicians who bid for the Games promised would be helped by the event. The Olympics should be creating enthusiasm and excitement, not mean-spirited petty-fogging. The spirit of the law, not its letter, should be the watchword.