I bought a new iMac and was in the process of reorganising my backup data. I placed two iPhotos libraries onto the the new hard drive with a view to transferring them to a new backup disc . They were automatically placed into the documents folder . I had clicked the preference to include desktop and document in iCloud prior to this although it was never my intention to upload these libraries which contains 15000 photos I did not have enough storage and did not want to put them there anyway. I was also in the process of transferring high quality audio files from the backup hard drive to a new disc but was continuously interrupted by error message which seem to be exacerbated by being connected to iCloud. I disconnected the documents folder from iCloud and did not think the warning given indicated that I would be in any danger off loosing data. Subsequently the iPhotos libraries disappeared and were not retrievable without specialist help. After two weeks and contact with three apple support staff I was told the loss of data was completly my responsibility and they would do nothing . I have not had a response from the my questions about how this problem should ever have arisen . I have repeated the same situation to see what happens if an iPhotos file is placed in documents then switched off from iCloud a warning is given that files will be moved to an archive file. (I think this warning may have changed from the initial warning I received in Nov ). An archive file is produced but does not contain the iPhotos library effectively loosing them. I am still trying to get a sensible response from Apple so far only being stonewalled.