While it isn't possible to cross out text in status updates or wall posts, you can easily cross out text when you create notes on Facebook. Crossing out text puts a horizontal line through traditional text, and allows Facebook users to apply a bit of expression when they express their thoughts in the website's notes feature. Crossing out text, also known as the "strikethrough" effect, can be executed by placing the appropriate HTML coding into the text you wish to cross out.
Log into your Facebook account, and click "Notes" on your profile's home page.
Select the "Write a New Note" button in the upper left corner.
Compose your note, adding the following HTML coding before and after the text you want to cross out:
<s>this is the text you want to cross out</s>
Be sure not to put spaces in between the code and the first or last letter of the words you want to cross out.
Click "Preview" button to verify the placement of your crossed-out text, then click "Publish."
Your note will be published, and the text which you chose to cross out will appear in the note.