From a web dev's perspective
When a customer processes a transaction through a website, their details and the details of the transaction are recorded in a database. Now because of data-retention laws (in Australia and presumably similar laws in the US and UK) we have to keep that data for a minimum of 7 years.
Not only that, but there is the issue of orphan records. For example, Customer X purchases Product Y and this purchase is recorded in Transaction Z. This transaction record contains a foreign key pointing to X and Y, so if either X or Y are deleted, Z becomes an orphan record with foreign keys to non-existent records. This situation quickly becomes a DBA's worst nightmare.
Consequently, records have to be retained to keep the database intact. When a customer is "Deleted", what actually happens is that a "deleted" flag is set in the customer's record but the data is retained to preserve the database integrity. Also, we have to keep it for 7 years because if the Tax Office audits us we have to be able to show details, including who bought what, when, and for how much, for that period of time.
So if legislation like this passes, it's going to be a screaming problem for DBAs everywhere. Not only is it going to conflict with existing data-retention and taxation legislation, but enforcing it is going to leave databases with orphaned records. I hope that the legislators take this into account when they're drafting the bill for this law.