provides data from a private data source 115 to mashup server 101 fig2 illustrates a block diagram of a typical mashup 201 the mashup 201 includes web services 203 mashup 201 may also include web content 205 according to embodiments of the present invention mashup 201 also includes one or more sources of private data 207 and 209 fig3 illustrates the steps performed by a mashup creator according to embodiments of the present invention the steps of fig3 are performed by a human mashup creator with the aid of a computer and a mashup maker first the mashup creator creates a mashup preferably using a mashup maker including both web services and private data as indicated at block 301 rather than uploading to the mashup maker the private data itself the mashup creator leaves a place holder for the private data as will be explained in detail hereinafter according to the present invention the mashup subscribes to the private data as if it were public web content the mashup may include web content as well as private data then the mashup creator tags the placeholder or holders with the data type format and data elements of the private data required for the mashup as indicated at block 303 then the mashup creator deploys the.