“Free OneDrive storage will decrease from 15 GB to 5 GB for all users, current and new. The 15 GB camera roll storage bonus will also be discontinued. These changes will start rolling out in early 2016.”

If you want to try to keep your 15 GB free storage space, and possibly more, Microsoft has posted:

“…we’re making it possible for you to keep your base storage quota and camera roll bonus, even after the changes roll out.

“Click…and your account will not be affected when the amount of free storage changes from 15 GB to 5 GB and the +15 GB camera roll bonus is discontinued.”

Some of the ways to do so is to:
regularly back-up files and data…
update software (operating systems, programs, drivers, etcetera)…
use anti-virus, firewall, anti-spyware, and anti-spam software…
and use connections that are secure (those that require passwords, and use passwords that are very strong).

For more information on the campaign go to http://StaySafeOnline.org