What Is PII? How to Protect Personally Identifiable Information in 2025

Personally identifiable information (PII) refers to any data that can identify a specific individual. In 2025, with AI-enhanced profiling, expanded data collection, and increasing digital interconnectivity, the sensitivity and risk profile of PII have grown significantly.

Cybercriminals target PII to commit identity theft, social engineering, and fraud. This guide explains what is PII today, the latest threats to its security, and how organizations can protect this information across internal systems and third-party networks.

What Is Considered PII in 2025?

PII includes both direct and indirect identifiers. It also can cover context-dependent data that can identify a person when combined with other information about an individual.

Common examples of PII:

• Full name
  
• Email address
  
• Social Security Number (SSN)
  
• Passport or driver’s license number
  
• Phone number
  
• Bank or credit card numbers
  
• Biometric data (fingerprints, facial recognition)
  
• Geolocation data
  

Modern data privacy laws and regulations such as the European Union’s General Data Protection Regulation (GDPR), California’s Consumer Privacy Rights Act (CPRA), and Brazil’s LGPD have broadened the scope of what qualifies as personal data. Increasingly, behavioral data (such as browsing history and purchase patterns) falls under the PII category when it can reasonably tie back to an individual. When linked to individuals, IP addresses and device identifiers may also qualify.

Data controllers and data processors both have specific roles in managing how PII is collected, stored, and shared. Controllers define the purpose and means of data processing, while processors handle data on behalf of the controller. Every organization that handles PII must consider its responsibilities under these definitions.

Why Is PII a Top Target for Cybercriminals?

PII is valuable to criminals because they can monetize it in multiple ways. Threat actors can sell it on the dark web, use it for identity theft and account takeovers, or craft convincing phishing campaigns targeting both individuals and companies.

Key motivations for PII theft include:

• Gaining unauthorized access to financial accounts
  
• Submitting fraudulent tax returns or insurance claims
  
• Creating synthetic identities
  
• Conducting espionage or politically motivated targeting
  

The combination of PII with leaked credentials, biometric data, or health records increases its value and risk. Data brokers, both legitimate and malicious, use sensitive information to build detailed digital profiles that are often resold without users’ knowledge. Data sharing between platforms and partners often occurs with minimal visibility for data subjects.

Threats to PII in 2025

Threat actors update their techniques and procedures as technology evolves. Key methods of compromising PII include:

• AI-powered scraping of publicly available data, including resumes, social media, and online directories
  
• Insider threats involving employees mishandling or stealing customer information
  
• Third-party breaches, when hackers compromise vendors holding sensitive data
  
• Internet of Things (IoT) and mobile device tracking, which expose behavioral and geolocation data
  
• Deepfake-based social engineering, where hackers can leverage stolen PII to impersonate executives or customers
  

Cloud service providers and other cloud providers add another layer of complexity. Organizations must implement security controls to protect data as it moves across environments. Continuous monitoring, identity management, and incident response plans must be adapted to defend sensitive data from these sophisticated attacks.

How to Secure PII Within the Enterprise

Securing PII requires a multi-layered approach that incorporates governance, technology, and employee awareness. It must align with data protection principles and uphold compliance with regional data protection laws.

Key controls include:

• Data classification: Clearly define and label PII across systems
  
• Encryption at rest and in transit: Ensure sensitive data is unreadable to unauthorized users
  
• Access control and least privilege: Limit data access based on role, time, and necessity
  
• Data loss prevention (DLP): Use DLP tools to detect and block unauthorized data movement
  
• Security awareness training: Teach employees how to handle, store, and share PII securely
  

Establishing an incident response plan that includes steps for data breach containment, notification, and recovery is also essential. These protections must extend to systems that process data and support both human and automated workflows.

Data protection officers (DPOs) play a critical role in ensuring that these activities comply with global data privacy laws and regulations.

Managing PII Across Third Parties

Organizations rarely manage all PII in-house. Vendors, partners, and service providers frequently process personal data on behalf of enterprises, which creates a broader attack surface. Managing third party risk management is crucial to protect data across interconnected environments.

Best practices include:

• Conduct vendor security assessments before onboarding
  
• Require contractual obligations for data protection and breach notification
  
• Continuously monitor third-party cyber hygiene
  
• Audit data flows to understand where and how PII is processed externally
  
• Require compliance with regulations and demonstrate that data protection impact assessments are completed
  

These steps help mitigate risks related to data sharing, shadow IT, and unmanaged data movement.

Regulatory Landscape for PII in 2025

PII is at the center of most global data privacy regulations. In 2025, updated and emerging frameworks continue to define strict requirements for data controllers, processors, and data subjects.

Relevant frameworks include:

• GDPR: Requires data minimization, consent, breach notification, and accountability for how organizations protect data
  
• California’s CPRA: Adds sensitive PII categories and enforcement mechanisms
  
• NIST 800-53 Rev. 5: Provides detailed controls for federal and enterprise environments
  
• ISO/IEC 27701: Privacy extension to ISO 27001, focused on PII controllers and processors
  

Maintaining documentation for data protection impact assessments and clearly defining roles for the data protection officer are part of a mature compliance strategy. Violations can lead to legal exposure, fines, and business disruption.

How PII Leaks Impact Business Resilience

Beyond compliance, mishandling personal data can damage trust, erode customer loyalty, and trigger downstream incidents. A data breach involving personal data often results in:

• Notification costs and legal liabilities
  
• Regulatory audits and settlements
  
• Loss of contracts or clients
  
• Negative media coverage and reputational loss
  

Organizations must build data security programs that treat PII protection as a strategic business requirement—not just a checklist. Properly handling sensitive information builds long-term resilience.

PII Protection in a Zero Trust Model

Zero trust architecture is increasingly essential for protecting PII across hybrid and multi-cloud environments. Alone, it can’t prevent all attacks. But it assumes no implicit trust and requires verification at every access point.

Key zero trust controls include:

• Identity verification with multi-factor authentication (MFA)
  
• Microsegmentation of sensitive data environments
  
• Ensure only trusted endpoints connect
  
• Continuous monitoring for anomalous access patterns
  

These measures protect data, prevent lateral movement, and detect malicious behaviors earlier. They are particularly effective in environments that process data across third-party networks or store sensitive data in cloud platforms.

Building a Future-Proof PII Protection Strategy

As the definition and value of personally identifiable information continue to evolve, so must the data protection strategies designed to defend it. Organizations that invest in protecting PII—through robust third party risk management, governance, and security—build trust and resilience.

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