Not everyone faces the same level of risk. A traveling journalist, a political activist, and a casual user will have different threat models. Begin by identifying what you need to protect and who might be trying to access it. 

Also: 5 warning signs that your phone's been hacked - and how to fight back

As the Electronic Frontier Foundation explains, your threat model should inform every security decision you make. Your device could be searched if you're crossing a border. Law enforcement might try to access your communications if you're attending a protest. Even if you're doing nothing wrong, the risk of exposure through routine corporate data collection is real.

Before implementing security measures, identify which threats are most relevant to your situation:

• Government agencies have considerable legal powers to search devices, especially at borders. US Customs and Border Protection can conduct basic searches without suspicion, though deeper forensic searches may require reasonable suspicion of wrongdoing. According to the CBP's policies, they can examine and review device contents without using specialized equipment in basic searches, but require supervisor approval for advanced searches involving data copying.
• Law enforcement capabilities vary widely. Some agencies use sophisticated tools from companies like Cellebrite that can extract data even from locked devices. These tools have become increasingly accessible to smaller departments and private entities.
• Corporate adversaries might seek intellectual property or business intelligence. This threat grows when traveling to regions known for corporate espionage or when attending industry events.
• Criminal actors target financial information, credentials, and personal data for fraud or extortion. Modern criminals employ increasingly sophisticated methods to extract valuable data from stolen devices.
• Specific individuals seeking access to your data pose a personal threat. These cases often require specialized protection plans if the adversary knows your details or habits.

Understanding your particular risks helps you prioritize appropriate protective measures. Implementing every possible security technique would make your device nearly unusable, so focus on measures that address your threats.

While not a complete security strategy alone, maintaining a low profile provides a valuable first layer of defense. Take these steps: 

1. Use a basic phone case. Device selection and appearance matters; choose a simple case without identifying stickers or affiliations. Consider using a device that doesn't immediately signal value or importance.
2. Keep devices secure. Your carry strategy should minimize visibility and accessibility. Keep devices in inner pockets or specialized anti-theft bags, particularly in high-risk areas.
3. Consider a decoy device. Using a "clean" secondary phone with minimal personal information for public use or border crossings can be an effective strategy for high-risk situations. Some security researchers recommend this approach for international travel, noting that you can often take your sim and buy a burner at your destination, depending on your destination.
4. Minimize attention-drawing behavior in public spaces. Use privacy screens to prevent shoulder surfing and avoid accessing sensitive accounts on public networks without protection.
5. Be alert to social engineering attempts from individuals who may approach with seemingly innocent requests to borrow your phone. These interactions can serve as pretexts for theft or installing malicious software.

These precautions might seem excessive for everyday situations but become crucial safeguards when operating in high-risk environments or when targeted surveillance is possible.

Practice regular digital hygiene to minimize vulnerability if your device is accessed. 

For example. audit and remove unnecessary apps regularly, especially those with access to sensitive data. The Electronic Frontier Foundation advises deleting sensitive photos, messages, and emails that aren't necessary before entering high-risk situations.

You should also implement data minimization principles. Store only what you need on your device, and transfer sensitive files to encrypted storage before removing them from your phone.

Also: 10 passkey survival tips: Prepare for a passwordless future now

Review authentication methods for your most critical applications, as well.

While biometric access (fingerprint/face unlock) is convenient, it can be used to access your phone without your consent. In fraught situations, disable biometrics and rely on strong passwords that cannot be physically compelled from you. This is particularly important when crossing borders; as a recent AP News report noted, "a border agent could simply hold your phone up to your face or force you to press your finger onto your device."

You also need to clear browser data regularly, including history, cookies, and cached data. I suggest using private browsing mode when accessing sensitive information.

Another measure you can take is to enable app-level security features where available, including PIN locks, automatic logout timers, and encrypted storage options. You should audit your cloud synchronization settings, too. Many apps silently upload data to cloud services. Review what information your device backs up automatically and disable synchronization for sensitive content.

Finally, develop a pre-travel checklist if you move between security environments regularly. Include steps like logging out of accounts, disconnecting from cloud services, and enabling airplane mode in sensitive locations.

Your online footprint can compromise your security even if your device is properly protected. Here's how to improve it: 

• Conduct privacy audits across all platforms. Review and restrict visibility settings for posts, photos, friends lists, and personal information.
• Address historical content vulnerabilities. Use platform tools to delete or archive old posts containing sensitive information, location patterns, or personal details.
• Remove metadata from photos and videos before sharing. Most digital images contain EXIF data with precise location coordinates and device information.
• Control facial recognition and tagging settings. Configure platforms to require your approval before others can tag you in content.
• Audit connected applications that have access to your social accounts. Third-party apps you authorized years ago may retain access to your data.
• Implement strong authentication on all accounts. Use two-factor authentication with authenticator apps rather than SMS, and employ unique passwords for each platform.
• Consider strategic deactivation during high-risk periods. Most platforms allow temporary deactivation without permanent account deletion.
• Evaluate messaging security on social platforms. Standard social media direct messages rarely offer end-to-end encryption by default. Migrate sensitive conversations to secure messaging applications.

When you travel, you pack light -- the same logic should apply to your phone. Log out of unnecessary accounts, delete sensitive files, and avoid syncing full cloud backups. Consider using a "travel phone, " a secondary device with only essential apps and data.

It's also wise to remove saved Wi-Fi networks and Bluetooth pairings. Uninstall browser extensions and disable auto-downloads. You can't lose what you don't carry. CNET advises removing yourself from data brokers to minimize your digital footprint further.

Regular text messaging is not encrypted. Instead, use end-to-end encryption apps to protect your calls, messages, and metadata. 

Also: 5 tools I trust to keep my online conversations private and anonymous

Signal offers secure, open-source messaging and calling. It's trusted by journalists, researchers, and activists worldwide. Matrix (via Element) is a decentralized protocol for secure messaging. It's useful for group chats and can be self-hosted for maximum control. Proton is a suite of privacy tools including encrypted email, calendar, file storage, and VPN -- all designed for strong user privacy.

Apple and Google have taken markedly different -- but, interestingly, increasingly aligned -- approaches to end-to-end encryption with their Advanced Data Protection features. 

Apple's Advanced Data Protection, introduced for iCloud, expands encryption to nearly all categories of user data, including device backups, Messages in iCloud, and Photos, ensuring only the user holds the decryption keys. Google's similar feature for Android and Google One backups also enables client-side encryption, meaning not even Google can access user content stored in the cloud. 

Also: Why rebooting your phone daily is your best defense against zero-click attacks

While the implementations differ under the hood, the direction is clear: Both tech giants are moving toward a future where users, not companies, control access to their most sensitive digital information. This shift, while a win for privacy, raises tough questions about lawful access and the balance between user security and public safety.