BlackBerry users in Canada and the US have launched legal action against Research in Motion (RIM) over the recent service outage, which left millions of users across the world unable to access web or email services for four days.

The US lawsuit was filed on Wednesday in a federal court in Santa Ana, California, and is on behalf of all BlackBerry owners in the United States who had an active service agreement at the time of the disruption. It accuses RIM of breach of contract, negligence and unjust enrichment, according to Reuters.

A similar lawsuit has been launched in Quebec Superior Court on behalf of all BlackBerry users in Canada. Both lawsuits claim RIM "is responsible for Blackberry users’ loss of email, BB, and/or internet service for approximately one and a half days".

RIM has not yet commented on the lawsuits.

The service disruption began on Monday, October 11th and although RIM claimed to have identified and fixed the issue within a few hours, the service collapsed again a few hours later. The service wasn’t fully restored until Thursday of that week.

Initially it was customers in the EMEA region that were affected but the outage soon spread to India, South America, the US and Canada, RIM’s homeland.

The outage was caused by a "core switch failure" in its UK operations, RIM said. The company apologised through Robin Bienfait, its CIO, and then both CEOs, Mike Lazaridis and Jim Balsillie.

The only compensation offer so far from RIM has been free premium apps to disgruntled customers.

However a CBR survey on the service disruption revealed that 18% of BlackBerry users were already in the process of moving away from the platform, while a further 34% believe they should consider switching to an alternative mobile platform after the outage.

The survey revealed that 58% of users are looking at either an iPhone or iPad as an alternative to BlackBerry devices.

Meanwhile RIM has delayed an update to its PlayBook tablet and also revealed that the software upgrade will not bring its popular BlackBerry Messenger (BMM) tool to the device.

The PlayBook, introduced as competition to Apple’s iPad, has been beset by poor sales and disappointing reviews. The current version of the device does not come with email, calendar and contact capabilities in-built; instead the device has to be hooked up with a BlackBerry smartphone. BlackBerry PlayBook OS 2.0 was supposed to address this issue but the company has again delayed its release.

"As much as we’d love to have it in your hands today, we’ve made the difficult decision to wait to launch BlackBerry PlayBook OS 2.0 until we are confident we have fully met the expectations of our developers, enterprise customers and end-users," said David Smith, a senior vice-president for the PlayBook.

It is now expected to be released in February next year, RIM said.