I like your answer because you&#x27;re describing a new threat model: an adversary tries to subvert the encryption process. Their service does not protect against such a threat.<p>Securing the data center is the least of your worries for such an attacker. I&#x27;d detail additional attacks that all subvert the encryption process:<p>1. Compromise the site&#x27;s private SSL certificate. This allows the possibility of MITM attacks. There is some evidence that NSA is already mounting such attacks on the Internet.<p>2. Malware on the client-side. A compromised browser, or a compromised OS.<p>3. The US government mandating that NSA installs hidden firmware on all data center servers.<p>I argue that strong semantics are extremely important when building secure services. I thought their service offers one such semantic: client-side form data encryption. They do not offer JS code integrity or any guarantees about the client-side encryption not being subverted.<p>By telling people about datacenter security and then calling it a &quot;a detail that some people who are security-conscious might care about&quot; or &quot;data center security probably does matter&quot;, you continue to raise the fog of confusion in people&#x27;s minds. Instead, the FAQ could educate the users and separate client-side encryption (which is what the service offers) from client-side code integrity (which the service does not offer).