Legal anti-ad-block software enables publishers to display pop-up or popunder ads even when users have ad blockers installed. These tools work by circumventing or bypassing ad blockers using techniques like script obfuscation, server-side rendering, or non-traditional ad delivery methods. Some popular solutions include AdRecover, BlockAdblock, and AdShield. Legality depends on regional privacy laws (like GDPR or CCPA), so compliant software must avoid tracking without consent and provide clear disclosures. Publishers using such tools should inform users and allow opt-outs to remain within legal boundaries. While pop-up ads can be seen as intrusive, using anti-ad-block software legally ensures revenue protection while respecting user rights. It's best suited for publishers who rely heavily on ad-based monetization but wish to stay within regulatory limits.