Tenants can't verify if rent-increase percentages comply with local rent control

In cities with rent stabilization or control (NYC, SF, LA, dozens of others), allowable annual rent increases are set by local boards and vary by building registration date, unit type, and improvement history. When a tenant receives a rent increase notice, they have no practical way to verify if the stated percentage is legal. The tenant would need to know: the building's registration status, the base rent, the history of prior increases, any Individual Apartment Improvements (IAIs) filed, and the current year's guideline rate. This information is scattered across municipal databases, many of which have no public search interface or are years out of date. So tenants either accept illegal increases out of ignorance, or hire a tenant attorney at $200-$400/hour for what should be a simple lookup. This persists because rent regulation databases were built for government compliance, not tenant access, and landlords benefit from the information asymmetry.