To ignore a person on Facebook, simply hide their updates and notifications, block them or unfollow them. On Twitter, users can also block or mute followers that appear in their main update stream.
To hide Facebook users, simply click on the "v" shaped arrow that appears to the right of the person's latest status update. A dropdown menu appears with the choices to block, unfollow or turn off notifications. Once a user's notifications are hidden, blocked or turned off, their status updates no longer appear in the data feed. These changes can be undone at any time. Friends can be ignored as well as postings from specific companies or public pages. Unfortunately, Facebook ads cannot be ignored, but when individual ads pop up, they can be hidden or turned off for that particular company.
Similarly, on Twitter users can be blocked or muted by clicking on the user's name. On the person's profile page, click the small icon that looks like a gear shift. A dropdown menu appears that offers the choice to block, report, mute or turn off retweets from that person. Users can also be muted when their tweets appear in a twitter stream. When the person's status update shows up, click on the word more in the bottom right of the tweet, and the option to mute or block the person appears.