1. A computer implemented method comprising: detecting a file content update on a first client computer system, the file created by a first application and the file to be synchronized on a plurality of different client computer systems in a plurality of formats; associating a security policy with the file, wherein the security policy includes restrictions to limit certain actions that can be performed with the file, wherein the security policy applies controls to the file resulting in transformation of a format of the file to one or more of: a clear text, unprotected file, an encrypted file with controls associated with it, restricting one or more of: who may access the file, where, on what device, at what time, and what operation that user may perform on said file, or a link or shortcut to a controlled online version of the file; propagating the file content update to each of the plurality of different formats of the file, comprising transforming the update to corresponding updates for each of the plurality of different formats of the file; synchronizing the file content update in a second file having a second format to a second client computing system, wherein the second format is compatible with the security policy and with a second application of the second client computing system, and wherein the security policy is applied to the second file in the second format to provide controls for enforcement of the restrictions at the second client computer system and the second file with the applied security policy is transferred to the second client computer system; detecting an update to metadata of the file from one of the plurality of different client computer systems, wherein the updated metadata comprises an update to the security policy; propagating the metadata update through each of plurality of different formats of the file; and distributing the controls derived from said metadata update to the file to each of the plurality of client computing devices comprising determining whether the update to the metadata can be applied to an existing file, and when the update to the metadata cannot be applied to the second file on the second client computing system, causing the second client computing system to acquire a new copy of the file in a different format.