I was trying to post a message on Facebook on the wall but didn't know what to press so I tapped just outside the box and suddenly a number added itself to my message which I recognised as one of my credi cards which I quickly deleted.How could this happe

Question

I was trying to post a message on Facebook but didn't know what to press as I don't often use it, so I tapped edaround the message hoping this would work but what happened was that a line of numbers were added to th message which I recognised as one of my credit cards.As I have never bought any thing on Facebook and I try not to store my cards I quickly deleted the numbers from the message and finally posted my  message by pressing the return key on my Ipad. Can you tell me where my credit card number came from?

Answer 1

The clipboard is a place in memory where text that has been copied from is temporarily stored ready to be pasted elsewhere.
The clipboard cannot be viewed, and is essentially invisible to the user. Copied text will stay on the clipboard until it is replaced by the next piece of copied text.
Probably what happened is you copied your credit card number from somewhere, either intentionally or accidentally (perhaps you made a purchase on your iPad using this card recently), and the clipboard stored the number. Then, whilst you were using Facebook you (accidentally) pasted this credit card number from the clipboard into your Facebook message.
That's the only likely reason I can think of. Hope I explained it well enough!