observers to ensure agreement, by webcam or passing around a table, or the process may be private. In the US only Massachusetts and the District of Columbia give anyone but officials a legal right to see ballot marks during hand counting. For optical scans, the software has rules to interpret voter intent, based on the darkness of marks. Software may ignore circles around a candidate name, and paper dust or broken sensors can cause marks to appear or disappear, not where the voter intended. Officials also check if the number of voters checked in at the polling place matches the number of ballots voted, and that the votes plus remaining unused ballots matches the number of ballots sent to the polling place. If not, they look for the extra ballots, and may report discrepancies. Secure storage to enable counts in future If ballots or other paper or electronic records of an election may be needed for counting or court review after a period of time, they need to be stored securely. Election storage often uses tamper-evident seals, although seals can typically be removed and reapplied without damage, especially in the first 48 hours. Photos taken when the seal is applied can be compared to photos taken when the seal is opened. Detecting subtle tampering requires substantial training. Election officials usually take too little time to examine seals, and observers are too far away to check seal numbers, though they could compare old and new photos projected on a screen. If seal numbers and photos are kept for later comparison, these numbers and photos need their own secure storage. Seals can also be forged. Seals and locks can be cut so observers cannot trust the storage. If the storage is breached, election results cannot be checked and corrected. Experienced testers can usually bypass all physical security systems. Locks and cameras are vulnerable before and after delivery. Guards can be bribed or blackmailed. Insider threats and the difficulty of following all security procedures are usually under-appreciated, and most organizations do not want to learn their vulnerabilities. Security recommendations include preventing access by anyone alone, which would typically require two hard-to-pick locks, and having keys held by independent officials if such officials exist in the jurisdiction; having storage risks identified by people other than those who design or manage the system; and using background checks on staff. No US state has adequate laws