Sub-postmasters used Post Office supplied Fujitsu Horizon tills.
Bank customers use online banking supplied websites.
Fujitsu had remote access to sub-postmasters' tills.
Various companies have remote access to your online banking pages.
Fujitsu's systems could execute code in tills due to a backdoor
available to their systems.
Various companies' servers can execute code in the online banking page,
on your web browser, due to a backdoor to their servers that the bank
gave them.
Code used allowed Fujitsu to falsify till records and the resultant
records appeared as the actions of the sub-postmasters.
Various companies' code can read your login credentials, banking details
and perform online banking actions, with any records appearing as you.
Invented cash discrepancies left in the tills were blamed on
sub-postmasters.
Any malicious banking activity will likely be blamed on banking
customers, data thefts may be used for fraud such as identity theft and
a ransomware attack may be easy to achieve.
Fujitsu were a highly respected and reputable tech company.
The various companies are a mix of web startup, social media, analytics,
major tech and foreign companies.
Sub-postmasters were financially ruined and some jailed.
What will happen to you if someone else can use your online banking as
you or control the online banking page you are looking at?