Unfortunately, with the right forensic tools it is possible to view some of the data that's on a device that's unencrypted and in plain text (documents, images, etc) Apple makes it pretty tough to get to it, but it's not impossible. Special but affordable devices know what to do and what to look for.And I thought that factory reset would delete all my data
Indeed, multiple wipes will write data over the same areas on the storage, making it a lot harder to properly restore the original data there. But I think that a lot of people don't know how to do this.The only option is to completey wipe software from mobile and install new software.