Is pixel tracking illegal?

Pixel tracking is not inherently illegal, but regulations impose requirements. Like maritime signaling, the technique itself is neutral; compliance depends on how you use it and whether you're transparent about it.

Under GDPR, tracking requires lawful basis (consent or legitimate interest) plus disclosure. You must explain tracking in your privacy policy. Under ePrivacy Directive, some EU countries require explicit consent. CAN-SPAM doesn't specifically address pixels but requires honest practices.

Best practice: disclose pixel tracking in privacy policies, honor opt-out requests, consider legitimate interest assessments, and recognize that Apple MPP and similar tools are making pixel data less reliable regardless of legality. Focus on engagement metrics you can trust.