Worrying :O
You obviously have no idea how many card details are leaked online on a daily basis.
When was the last time PCS had an independant penetration test done? im sorry but SSL doesnt protect against stored data.
Regulations protect the consumer, things like PCI compliance (the need to encrypt cardholder data) - organisations over a certain size are mandated to comply or face financial penalties from the card schemes (most noticeably the inability to chargeback fraud to the schemes).
In short, if you yourself take reasonable care when you transact then you are covered by the scheme guarantees that are in place for you and your bank. Worst case you may need to change your card if a breach ever occurred, but you shouldn't financially lose out. If the risk was yours then you would you would be crazy to EVER transact online.
That we know PCS hasn't ever suffered any data breach, and that we've seen there are many satisfied customers posting to this forum where nobody has mentioned their card data going astray. This is a good sign and should give you confidence. You've much more chance of someone skimming your card information at a restaurant or petrol station - so breathe deep and trust in the system!
If it helps, I once spent £47K on my debit card