Relax OP_RETURN standardness restrictions

In a detailed discussion on the challenges posed by spam in a permissionless blockchain system, several key points were highlighted regarding the inevitability of low-value spam due to the nature of these systems and the strategies employed by spammers. It was noted that removing OP_RETURN restrictions could potentially invite another wave of spam, underscoring the cyclic battle against such nuisances. The economic aspect of spamming, fueled by the continuous flow of easy money within the economy, ensures a persistent emergence of new spammers as old ones are phased out. This cycle is further exacerbated by the attention spammers receive from media and influencers, thereby making their activities more profitable.

The conversation delved into the technical difficulties of filtering spam in permissionless systems, where encoded data poses significant challenges for detection and filtering. The point was made that creating effective filters against spam is an ongoing, never-ending task, given the adaptability and persistence of spammers. However, it was argued that not all spam needs to be countered; instead, a strategy of displaying active hostility towards spammers could deter the most disruptive schemes, particularly those relying on consistent transaction formats. By targeting these specific offenders with tailored filters, it's possible to disrupt their operations significantly, causing them to move their activities elsewhere. This approach is seen as effective against spams that require considerable coordination and financial investment, thus inflicting financial losses on those attempting to launch spam schemes that are easily detected and filtered out.

Furthermore, the discussion identifies a distinction between different types of spam, acknowledging that high-value spam, which mimics real financial transactions, presents a unique challenge. To mitigate the impact of such spam, more drastic measures, like reducing block sizes, were suggested. However, concerns were raised about the potential negative effects on bitcoin's usability for regular transactions, especially during periods of fee spikes. The impact on new users and the overall accessibility of bitcoin, including the challenges associated with onboarding users to solutions like Lightning Network during these times, was highlighted as a significant concern.