Relax OP_RETURN standardness restrictions

The ongoing discussion in the Bitcoin Development Mailing List addresses the critical issue of spam attacks on the Bitcoin network, a problem that isn't new but has escalated significantly due to certain decisions by the core development team. Historically, Bitcoin has faced several spam attacks, which were effectively countered by the core developers' proactive measures to write and implement filters against new abusive transaction formats. This deterrence strategy showcased the developers' determination and resulted in the spammers shifting their focus away from Bitcoin, as detailed in an analysis by BitMEX. The narrative underscores the importance of not yielding to such adversarial tactics, emphasizing the need for continued vigilance and action to maintain Bitcoin's integrity as a premier medium of exchange and store of value.

A notable point of contention within the community is the rejection of a proposed pull request (PR) by Luke-jr, aimed at filtering transactions exploiting the witness discount through specific operational codes. This decision signaled a departure from the previously aggressive stance against spam, inadvertently encouraging altcoin Ponzi schemes to target the Bitcoin blockchain with spam. This lax approach has led to a significant increase in spam, adversely affecting new user onboarding and disproportionately impacting users in economically disadvantaged regions due to rising transaction fees. The refusal to adopt new filters against these spam transactions has created a perception of tacit approval for such schemes, further exacerbating the issue.

Critics of transaction filtering argue against the censorship of transaction types that demonstrate economic demand, ignoring the fact that the demand was fostered by Bitcoin core's ambivalence towards combating spam. This stance has not only facilitated the proliferation of Ponzi schemes but also demoralized developers willing to contribute to spam mitigation efforts. These developers are ready to write filters for emerging spam formats, but the core team's reluctance to incorporate these solutions undermines their efforts and discourages active participation.

The blog post emphasizes the urgent need for a strategic shift to re-engage with active spam filtering to prevent the blockchain from being overwhelmed by spam, which would compromise Bitcoin's utility and value. Highlighting the significance of the Lightning Network as a transformative development, it calls for a collective effort to combat spam aggressively, drawing lessons from past successes to secure Bitcoin's future as a dominant medium of exchange and potentially the global reserve asset. The situation presents a crossroads for Bitcoin, where the choice between confronting spam proactively or succumbing to it could determine the currency's trajectory in the years ahead.