vulnerabilities of an e-commerce based application

http://www.zignals.com/main/

The above website is a market place for stock brokers strategies,

would anybody be able to tell me the vulnerabilities associated with a website like this.

I would like to set up a website like this and i would like to know the protection that i would have to include in my programming to ensure against any sort of malicious attacks on the website or web services provided.

update of question

The above website uses开发者_StackOverflow microsoft's silverlight technology, what would an attacker have access to enable a successful hack of the site.

so my question would be , what are the vulnerabilities of the using silverlight as a web technology.

the website provides information on strategies for stock brokers, how would you protect this information from attackers.

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The full answer to your question wouldn't even fit in one book. You have to take care of everything, from physical security of your data center to the smallest details of your HTML templates. This is like asking: "There's this bank down the street and I want to have a similar one. How do I make it secure?" I wouldn't even know where to start. Do you have any specific question? If so then I'll try to update my answer.