Copy some rich text from (the read version of) Wikipedia or another website. Paste it into the visual editor. Formatting like bold and italics will copy properly, but links won't.

For example, take the first sentence from enwiki:The New York Times: "The New York Times is an American daily newspaper...". If you paste it into a content editable sandbox, you'll get the correct HTML:

<i style="color: rgb(37, 37, 37); font-family: sans-serif; font-size: 14px; line-height: 22.4px; background-color: rgb(255, 255, 255);"><b>The New York Times</b></i><span style="color: rgb(37, 37, 37); font-family: sans-serif; font-size: 14px; line-height: 22.4px; background-color: rgb(255, 255, 255);">&nbsp;(</span><i style="color: rgb(37, 37, 37); font-family: sans-serif; font-size: 14px; line-height: 22.4px; background-color: rgb(255, 255, 255);"><b>NYT</b></i><span style="color: rgb(37, 37, 37); font-family: sans-serif; font-size: 14px; line-height: 22.4px; background-color: rgb(255, 255, 255);">) is an American daily&nbsp;</span><a href="https://en.wikipedia.org/wiki/Newspaper" title="Newspaper" style="text-decoration: none; color: rgb(11, 0, 128); font-family: sans-serif; font-size: 14px; line-height: 22.4px; background: none rgb(255, 255, 255);">newspaper</a><span style="color: rgb(37, 37, 37); font-family: sans-serif; font-size: 14px; line-height: 22.4px; background-color: rgb(255, 255, 255);">...

But if you paste it into the visual editor, the link on "newspaper" won't be copied.

Seen on enwiki and the beta cluster using Chrome and Firefox.