Troy Hunt explains Subresource Integrity (SRI) using an example of loading jQuery from a third party. SRI enables developers to verify a third party resource is not comprised by comparing it to a known-safe local resource. I've never heard of this feature, and browser support is really weak right now, but it could prove useful once support is improved. However, I can imagine all kinds of scenarios where false-positives could occur. Still, it's a fascinating study.