The recent news that Visto has won a patent claim against rival mobile email provider Seven Networks will have come as little shock to IT Week readers. These unseemly fights over so-called intellectual property rights are now such a regular occurrence in the US that they barely register on the radar of seasoned IT industry watchers.

Neither will the news that the victorious Visto is now gunning for BlackBerry-maker RIM elicit much surprise. RIM has itself just emerged from a bruising legal tussle with another company over a separate patent dispute regarding mobile email.

These cases often end with the two parties agreeing a compromise, with each gaining access to some of the other’s intellectual property. In its recent fight with NTP, RIM found it had little choice but to pay a large sum of money to settle the case, despite the US patent office overturning all of the patent claims in question. This probably seemed a better course of action than risking an injunction that would severely hit users of its BlackBerry system.

But the Visto case could prove a greater threat to both developers and users of mobile email than you might imagine. Visto has been developing technology for wireless email systems for about a decade, and believes it has patents that are not only being infringed by RIM, but by just about all mobile email systems on the market.

Visto claims to have patents covering synchronisation of data on a mobile device with a data source behind a corporate firewall. This might seem like an absurdly broad claim, but the fact remains that a US jury found in Visto’s favour, and the company is now going after RIM, Microsoft, and Good Technology.

I’m no legal expert, but it concerns me that Visto’s claims seem to be so broad that it could be impossible to build any wireless email service that does not infringe the patents in question. In other words, the US government may have handed Visto the right to stop rivals from competing in the mobile email market.

And in case you are thinking this won’t affect users in Europe, where patents on software and business processes do not apply, think again. Almost all of the big mobile email developers are based in the US, and so it is theoretically possible to put them out of business through related legal actions.

If the maker of your company’s mobile email system were to disappear tomorrow, it might not affect you immediately, but the flow of security patches and maintenance updates would cease, and you would eventually be forced to rip out the system and replace it.

If I were a BlackBerry user, I’d keep a close eye on the situation.