Google is rolling out a new feature on their Google+ platform that would highlight your +1ed posts to people who have you in their circles.
This is an opt-out feature as it is enabled by default on all user accounts. The worst part is that you cannot disable this feature in your own streams.
Google is offering one option though. You can stop sharing your +1ed content to people who follow you.
You can block it completely to restrict it to individual circles or profiles.
The options is available from here:
This can also be done from the Google+ mobile app. Go to settings > sharing and the same option is available.