Possible security problem with Player Auctions

To sell a runescape account on PA it asks you to upload a form of ID.

I was looking on the PA runescape accounts and (long story short) was able to see the uploaded ID of the seller, I contacted 3 different members of their live support team but all 3 gave the same message, "its impossible". I gave them a printscreen of my computer and even recorded it on my phone but they just disconnect.

After about 20 attempts at it(wont disclose method but it simply involves clicking 1 button when viewing somebody else's account) I was able to see 5 uploaded ID's that contained Name, Address and other sensitive information.

Is this a big deal or not?

My skype is Meerkatmad123

To me, this seems incredibly fishy to I immediately took my ID down from the website.