While this lets those who are going far above and beyond to gather information, the solution is for the storage numbers to be published market-wide, to take away the edge a few have - with enough market pressure this could possibly happen.

Arbitrage is valid, as is doing your research, inferring what's going on with a company and then trading on your assumption.

Insiders are barred from influencing the market with their knowledge, but outsiders who infer what they think is going on, whether it's a sure thing or not, are perfectly fine.