The $2 billion trading loss that JPMorgan Chase disclosed late on Thursday provided ample ammunition for supporters of the Volcker Rule, which would restrict government-backed banks' ability to conduct proprietary trading. But it also prompted a fair amount of finger-wagging toward the company, given JPMorgan's stance as one of the rule's fiercest opponents. JPMorgan has been among the most outspoken detractors of the proposed financial regulation that is making its way through Washington. The firm has laid bare its feelings about the Volcker Rule several times, including in a Feb. 13 comment letter to the Federal Reserve. In that document, JPMorgan argued that the proposal would restrict its efforts to rein in risk-taking and would harm the firm's ability to compete against foreign rivals that did not face the same restrictions. In the letter, JPMorgan specifically mentions its chief investment office, the trading group which caused the $2 billion trading loss. JPMorgan also happens to run one of the most active and best-financed lobbying operations within the commercial banking industry. In the first four months of 2012, the firm has spent $1.92 million, barely trailing Wells Fargo in terms of banks' lobbying expenses. Last year, JPMorgan spent $7.62 million; two years ago, it spent $7.41 million, the most in its industry. And JPMorgan's chief, Jamie Dimon has been among the most frequent visitors to Washington to press his case.