You can't, as far as I know. If people want to hide the stuff you post, they have to do it. You can't hide it from them.
You can control the information that others see in your privacy settings. You can control it for one individual or you can put a bunch of people into a group and control the settings for the entire group [such as classmates].
eta instructions ~
Customizing your Privacy Settings. I
SETTINGS
PRIVACY
PROFILE
Under profile you can go to the drop down box for each category and customize who can view each thing. You can customize it by groups of friends or just eliminate one or more of your friends. Each category can be customized individually.
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From Facebook help on this subject ~ It appears you can create a list of friends that you want to have Limitations on what they can view on your pages.............
To add someone to your Limited Profile list, follow the steps below:
1. Select "All Friends" from the Friends drop-down menu.
2. Click on the "Limited Profile" Friend List in the left sidebar. If you do not see a "Limited Profile" friend list in this section, you can create one by clicking the "Make a New List" button and then naming the list.
3. Type your friend’s name into the "Add to List" field. You must be friends with a person to add him or her to the Limited Profile list.
To prevent users on this list from seeing certain content, please follow the steps below:
1. Click the "Privacy Settings" option in the Settings drop-down menu at the top of any Facebook page.
2. Go to the Profile section.
3. Select any Profile privacy setting and click "Edit Custom Settings."
4. Enter the name of your limited profile friend list in the "Except These People" section to restrict these users from viewing the profile content you selected.