Yesterday, Apple blocked Samsung’s Galaxy Tab in the EU as it had in Australia previously. Today, it is blocking Motorola’s XOOM.

According to Reuters, this is a high risk strategy for Apple maintaining its market share lead. The cases could take months, if not years to come to court and Apple will have to provide more substantial evidence in subsequent court cases that the design of the Galaxy infringed its patents or copied their designs in order to make any bans permanent. So, they aren’t done deals. And if Apple Loses, it will owe Samsung a lot of money.

“Apple has a strategy of filing patents, getting some protection and trying to prevent other people from entering the market in the short-term,” said Nathan Mattock, an intellectual property lawyer at Marque Lawyers in Sydney. “If Apple’s wrong it will have to pay Samsung a considerable amount of damages, so it’s potentially quite risky.”

As a strategy to keep its marketshare, Reuters says that Apple is on the defensive and points to IDC’s numbers where iPad’s share of the market is expected to drop from 66% to around 58% by the end of the year.

Reuters notes however that Apple has the biggest war chest in the industry and how important it is to keep its marketshare “by whatever means necessary”.

“Using the courts is increasingly becoming part of commercial strategy in high growth markets where the opportunities are great — it’s a tactic to try and slow the competition down by whatever means you can,” said Frost & Sullivan’s Milroy.