Get your defense budget in balance with the threats. I guess this depends on the kind of content you post to the web. But then again we live in a world where social and bank info is apparently still up for grabs. Why put your money in security if someone else is giving the same info away?

Since you've already bought licences for SAP ERP, you could get a bargain on the Master Data Mgt component. It also offers support to control the Master Data harmonisation process, which you probably need if you have such a large amount of data.