Provider hosted app on SharePoint 2013 hosted in Office 365.

I have a situation where 
1. I have to read data from a SharePoint 2013 site hosted in Office 365 from a provider hosted app.
-- tried the MSDN example (http://msdn.microsoft.com/en-us/library/fp142381.aspx) getting Unauthorized exception while executing .executeQuery().

2. My App would consume data from a wcf data service using odata javascript library (datajs by codeplex).
-- OData.read({
            requestUri: "http://localhost:2030/WcfDataServiceOData.svc/Users?$top=1"
        },

Getting Access denied error. I can consume my OData from a normal ASP.NET app. but not from the SharePoint app.

can any one put some light on the above. Thanks.