Hi Frank
We have had a holiday home near Tortosa for four years now and (touch wood) we haven't had any problems.  Obviously everything is locked up when we are away and we are very lucky having fantastic friends who keep any eye on it as well as neighbours who have the plots either side.  I know that some people have been very unlucky and have been the victim of theft but that does happen everywhere.  Also if your property has grills on the windows and doors I think it deters any would be thieves.
Please don't let this put you off the area as it is lovely.

Debbie