How does ebay identify computers

[chesss]

I shifted cities a while ago , today I logged into my old ebay account , and had some problems with my account , because according to ebay this was a different computer from which i had accessed my ebay account earlier.

So anyway i had to go through a verification process to enable some features of my account.

This is what the ebay guy had to say about all this:

I have now added your computer to the list of trusted computers for your account, and you will no longer receive this block.

this got me thinking. exactly how does ebay maintain this list of trusted accounts? ip addresses are always changing. so how does ebay recognize the same computer ? mac-address or something?

just wondering....

 

[setu_garg]

its usually a combination of cookies, ip address (which your ISP gives you). Mac address might be used by some. Also, they can find out your location from your ip address. So a change in location might just have triggered that.

 

[chesss]

it can't be cookies, thats way to temporary.
ip address again me thinks are too temporary (255.0.0.0) . location sounds right though.
Is it possible for a website to see the mac address of a client ?