Or, you could not be a dick and not erase your friend's save file. You know?

I hope they fix that soon. PSN certainly has quite a few security flaws.

Oooh, I wonder if it allows friends to make in-app purchases!?!

You know, wonder into the menus, select downloadable content, and purchase a horse armor or a few dozen Ultimate Team packs...

Have you never used remote desktop? That's what share play is basically, except Sony was smart enough to lock out the console menu. Making changes to every game before they can be used for share play would be counter productive. Anyway Sony has given the tools to developers to do so as they stated that certain scenes can be blocked from share play by the game. Seems reasonable that game developers can block certain actions as well if they feel like it.

If you give them your password, sure they can. They won't even need share play :p
I doubt it would work with share play as those in app purchases usually launch the store which is locked out I think?

Share Play is exactly like handing your controller to your friend. Only difference is that it isn't across the couch, but over the internet instead.

I don't think Sony could be held accountable when you (very clearly) give your friend permission to control your console.

Next they're gonna say Share-Play allows friend to start a New save file on your friends system. Like, really Sherlock?

This is why you don't share things! xD

Haters gonna hate. If they don't lile Sony, they will say everything for put them in bad light. 

Really? The only way Sony can prevent this is with cloud save files. And they're here. If people act like dicks, you must blame the people and the people only.