Do you encrypt data? If your servers are compromised, will someone have access to all of my emails?

Even if that is the case, I might be more comfortable using Greplin if I knew more about your security practices. What procedures are in place to prevent my emails from being stolen?

Edit: I hate being the one to criticize an incredible idea that is the result of hard work. I feel obligated to add that I want to use Greplin and I probably will use it for Facebook and Twitter. (Facebook's built-in search is useless.) I really hope there is a way that I can use this for email too.

Personally, I find GMail's inbuilt search hard to beat. Its almost perfect. But I've used Greplin for Facebook (that's the only thing that I'm using Greplin for), and I find it to be an amazing service.

Doesn't Facebook already have a search feature?

Its fairly limited, feature-wise.

Do you store full copies of all data? What I mean is, if someone breaks into Greplin, can they effectively read all of my email assuming I've synced with Gmail? Or do you just index the data and reference sources using URLs?

Even if they just have an index without the full copy it's not that hard to reconstruct a version similar to the original just from the index, as in an inverted index you typically do not only store the documents of a term, but also the word number within the document. However, it's not possible to restore the original version exactly, due to things like stemmers.

often in text indexing the original document is kept for things like snippet generation.