Investment firm 'Salomon Brothers' is reportedly behind a massive Bitcoin dusting campaign, targeting over 39,000 addresses to reclaim 2.3 million dormant coins valued at $279 billion. According to Protos, the firm sent legal notices between July and August, using small BTC amounts and 'OP_RETURN' outputs to deliver the messages. The notices warned of 'constructive possession' claims against non-responding address owners. Galaxy Research analyzed the campaign, noting that it focused on P2PKH addresses, which are less susceptible to quantum attacks compared to P2PK addresses. The research suggests Salomon Brothers might be testing a new legal theory to assert ownership over the Bitcoin. Protos has previously raised concerns about Salomon's methods, likening them to phishing and pointing out potential red flags on the firm's website.