Deleted isn't gone.
Shredded is.

When you delete a file, Android removes the entry that points to it and marks the space as free. The data itself usually stays until something else is written over it, which can take days or months depending on how full the phone is.

Modern Android phones encrypt storage, which helps. But while the phone is unlocked, apps, backup tools and forensic software can sometimes recover recent deletions. Thumbnails, cached copies and chat-app media folders often survive after the original is gone.

Secure deletion closes that gap: overwrite the contents first, then remove the file, then re-wipe free space to catch copies left by earlier deletes.

• Delete thumbnails and cached copies, not just the original.
• Check chat apps for their own media folders and backups.
• Re-wipe free space after a big clean-up.

1. Back up what you want to keep, and check the backup opens.
2. Sign out of your Google account and Samsung or other maker accounts so the phone isn't locked to you.
3. Remove your SIM and memory card.
4. Shred sensitive files and re-wipe free space, and keep the certificate.
5. Unpair watches, earbuds and cars.
6. Run a factory reset from Settings.
7. Turn the phone on once more and check it opens at the welcome screen.

Doing a secure wipe before the reset means leftovers are overwritten, not just hidden.

Peter Gutmann's 35-pass method was designed in 1996 for magnetic hard drives. The US DoD 5220.22-M method uses 3 passes: zeros, ones, then random data. On modern phone storage, one verified overwrite already makes recovery very hard.

Extra passes exist because some workplaces must follow a named standard, and some people want extra assurance for a handful of very sensitive files.

• Quick (1 pass): everyday clean-ups.
• DoD (3 passes): selling or returning a phone.
• Gutmann (35 passes): when a policy requires it, on small numbers of files.

A phone is a key to the rest of your life. Someone with access to it can often:

• Reset passwords using your email and SMS codes, then take over banking, PayPal and social accounts.
• Use photos of your licence, passport or Medicare card for identity fraud.
• Read private messages and photos for blackmail or targeted scams against your contacts.
• Pull saved passwords, card details and addresses from browsers and apps.
• Track where you live, work and go from location history.

What helps: a strong screen lock, two-factor authentication through an app rather than SMS, keeping ID documents in an encrypted vault, and shredding what you no longer need.

Australian law already gives authorities several ways to access phones, and the rules differ by state:

• Search warrants: police can seize a phone under a warrant and, in several states, apply for an order requiring you to provide your PIN or biometrics. Refusing can be an offence.
• At the border: Australian Border Force officers can examine devices without a warrant.
• Proposed NSW changes: in June 2026 the NSW Government announced plans to let police seek Digital Evidence Access Orders in the field, such as at arrests and roadside stops, rather than only with a search warrant. At the time of writing the bill had not passed.

What this means for you: good privacy is about habits. Don't keep years of data you don't need, and protect the rest with encryption.

Important: never delete or alter anything once police, a court or a regulator has asked for it, or when you know it may be needed as evidence. That can be a serious criminal offence. PrivaShred is for everyday privacy, not for avoiding a lawful investigation. This article is general information, not legal advice.

1. Review app permissions: location, microphone, camera, contacts.
2. Delete apps you haven't used in 3 months.
3. Clear chat-app media folders of old photos and documents.
4. Move ID documents and sensitive scans into an encrypted vault.
5. Shred downloads you no longer need, such as bank statements and payslips.
6. Check for Android and app updates.
7. Confirm two-factor authentication is on for email and banking.