Restful web User Folders CMC permissions

I'm having some problems getting data returned from the platform restful web services. BI 4.1 SP3, what would the minimum permissions be for Top-Level security on the User Folders (ID 18) to allow the Restful web services to access a user folder id? I am trying <restful web url> biprws/infostore/18/children/?type=folder, but getting :" Info object with ID 18 not found. (RWS 000012)". The request for the root folder works file (/biprws/infostore/23/children/?type=folder). We are a multi-tenant shop. What i want to get back is only the user folders that a particular user owns (the user that makes the request/login token).