[aidos]

In that case your fallback isn't going to help - unless you're performing a checksum on the response you get from code.jquery.org.

I know it's probably not considered great practice anymore but I generally just self host js libs. One less thing to go wrong and I often develop without an internet connection. Saves on having to dropback to a fallack every time.

[raverbashing]

Yes, true, in the case of a compromise it won't help. But I've found that outages are more frequent (including my own internet connection)

So yes, it also is necessary for development without an internet connection.