Is it legal to cache public Instagram photos?

Question

There is a highload web application which is used by non-authenticated users.

Now it needs to show public Instagram photos filtered by some hashtag. There are many non-Instagram users. So is it legal to cache those public Instagram photos on my servers to increase performance and to avoid reaching of 5000 request per hour/CLIENT_ID limits?

Answer 1

Caching is specifically covered in the Instagram API Terms of Use:

2. You shall not:
...
Cache or store any User Content other than for reasonable periods
in order to provide the service you are providing to Instagram users.

So yes, it would appear legal to cache content provided it is for a reasonable period for performance purposes.

Caveat: IANAL