.ToString() as string;
When I entered a page from an app developed by a junior colleague and deleted a parameter from the query string, the app failed (no error handling was in place)
That's why: string where = Request["vdate"].ToString() as string;
I recommend beatings. And null checks.
I think null checking is forbidden.
Another example: byte file = (byte)reader["Image"]; // where reader["Image"] is null in like 10% of cases