Many times you have to agree with some conditions or terms on website by checking the "I agree" checkbox or clicking some button.
Or this - we are working on an agreement email for our client - our client sends email to their client with some kind of "I agree ..." checkbox to give our client approval to contact them and work with their credentials.
Both of these "approvals" can be faked very easily. When user clicks on confirmation
url or checks some
checkbox, it is just a
request sent to our server and we then do something with the request. I can very easily just change directly the value in our database which can't be decided (in terms of law) whether did that user or a database programmer.
If you can't prove who "approved" that, how could it have any legal weight and everybody use it?