[siva7891]

So Instagram copied Snapchat features.

Say Snapchat mentioned in its TOS that you should not use this product to copy the features under reverse engineering and it proved that Facebook employees did it. Does Snapchat has a legal claim?

[megablast]

Only if Instagram used the Snapchat app to create those features. If someone told Instagram about the feature, or they read about it online, and then implemented it, they are not reverse engineering it.

And you would have to wonder how it would work for simple features, that can be communicated in a few sentences.