You can block or limit the receipt of cookies through the options of your browser.
On Internet Explorer, click on "Tools" in the menu bar and then on the item "Internet Options". Finally, access to the tab settings "Privacy" to change your preferences regarding cookies.
On Firefox, click on "Tools" in the menu bar and then on the item "Options". Finally access the settings under "Privacy" to change your preferences regarding cookies.
Chrome, type "chrome://settings/content" in the address bar (without quotation marks), and change the settings for cookies as you want.
On Safari, select "Preferences" and then choose "Privacy". Under Block Cookie specify how Safari must accept cookies from websites.
If you use Safari on portable devices, like iPhone and iPad, you must instead do so: go on "settings" and then find the device "Safari" on the left menu. From here, in the "Privacy & Security", you can manage the options Cookie.
To disable cookies of external services you need to act on their settings: