If you have installed ios version prior then ios5 then no data will backup to cloud. Becouse i-cloud comes with ios5.
In ios5.0 you can stop your backup with following function
(BOOL)addSkipBackupAttributeToItemAtURL:(NSURL *)URL {
NSLog(@"in add skipBackUpAtrribute method.......");
const char* filePath = [[URL path] fileSystemRepresentation];
const char* attrName = "com.apple.MobileBackup";
u_int8_t attrValue = 1;
int result = setxattr(filePath, attrName, &attrValue, sizeof(attrValue), 0, 0);
return result == 0;
}