At competent companies -- I make no claim about Twitter here, but certainly at Google or at my employer -- it is extremely uncommon to have access to that database. All requests to access are logged and individually permissioned. Asking to access without a good reason, such as attachment to an active customer ticket, etc -- will get a hard no.
But at the same time, there's usually a way round it. For example, break the account in some way so the user opens a ticket, then grab the ticket and dump the whole contents of the account to 'debug'.
