SharePoint 2010 and 2007 have a known limitation where you can't access item level security metadata (for example permissions assigned at folders and list items) using the standard web services (sitedata.asmx, permissions.asmx, lists.asmx, etc). To overcome this, you have to install/deploy a custom web service which does that for you in the server side and then sends back the security information.
I'm trying to do the same in SharePoint Online (or SharePoint for Office 365) which is a version of SharePoint 2010 which runs in the cloud (either hosted by Microsoft of by your company).
The main change here is how authentication works, but besides that, you cannot install a custom web service into SharePoint online. So, the previous approach doesn't work.
Does anyone know of any alternatives to fetch this information?