Is possible to delete unwanted post from the Newsfeed using an Admin Account with Mange Social Data Rights.
These are the steps:
1. – Go to Central Admin
2. – Under Service Applications, go to Manage service applications
3. – Highlight the User Profile Service and select “Administrators on the Ribbon”
4. – Chose the admin account and check the Manage Social Data Permission
Now this admin account should be able to delete users posts