The language is amiable enough, it just isn't in any way a request, it's a statement that they believe their trademark is being infringed and that they will enforce it.
It is a overt threat of lawyers attacking if he does not comply.
Nothing "amiable" about it. It is a threat, pure and simple.
It's not unreasonable by any means.
Am I the one that's misunderstanding what polite means? It sounds like several people, including Kik, seem to think it's just how you word things. As long as you threaten someone with lawyers using polite language it's polite? I don't know about you guys, but if someone did that to me "polite" would be the furthest thing from my impression of the exchange.
"If you don't give me the thing I want then I won't be able to prevent myself from hitting you in the face." ... polite?