Players can view other player's complete champion mastery pages [Client]

Players can view other player's champion mastery pages (the entire champ roster). Since you can't directly see their roster, i assume this is a bug.

Repro steps:

1. view target player's profile via in menu prompt
2. return to your profile via top menu button
3. quickly view your "champions" page: it will show all the champs that the person owns and their mastery with each champion. Can be reproduced 100% of the time.

Picture 1: my champ mastery page Picture 2: a friend's champ mastery page (note same username/ip/rp in top right and MUCH more mastery of different champs)

Not really sure if it's worth fixing or if you already know about it, but I figured i'd report it anyway. Could have an impact in high level (diamond) play (probably not master/challenger as much though, they already seem to know each other)