How can I change permissions on multiple files?

BatChmod 1.6.3 is a utility that can help set the right permissions on a single file, folder, or folder of files. In your case you might try using it and checking the box to Clear ACLs and reset the proper permissions.

Be careful of its usage.

Repairing the permissions of a home folder in Lion is a complicated procedure. I don’t know of a simpler one that always works.

Launch the Terminal application by entering the first few letters of its name into a Spotlight search. If that doesn’t work, then in the Finder, press the key combination shift-command-U. The application is in the folder that opens.

Drag or copy – do not type – the following line into the Terminal window, then press return:

chmod -R -N ~

You may see a few error messages about an “invalid argument” while the command is running. You can ignore those. If you get an error message with the words “Permission denied,” enter this:

sudo !!

You'll be prompted for your login password, which won't be displayed when you type it. You may get a one-time warning not to screw up.

Next, boot from your recovery partition by holding down the key combination command-R at startup. Release the keys when you see a gray screen with a spinning dial.

When the recovery desktop appears, select Utilities ▹ Terminal from the menu bar.

In the Terminal window, enter “resetpassword” (without the quotes) and press return. A Reset Password window opens.

Select your boot volume if not already selected.

Select your username from the menu labeled Select the user account if not already selected.

Under Reset Home Directory Permissions and ACLs, click the Reset button.

Select  ▹ Restart from the menu bar.