WeChat ban is just evil, no justifiable benefit. Almost all the users in America are overseas Chinese who use it to talk to friends and family in China and send money.
Calling the ban evil is a bit hyperbolic IMO, or maybe just incomplete. Phones with the software could easily be compromised. Users with the software can be profiled and tracked by the Chinese government pretty easily. The Chinese market bans most of America's social media software, and we're entering a trade war. All these are real, legitimate reasons to ban it.
This is true of all apps coming out of the US with the NSA. Should Google, Facebook, Netflix be banned in Europe?
> and we're entering a trade war.
The trade war started a while ago and I'm pretty sure China is winning it.