The message, on its PayPal online payment unit's press and community website pages, did not say why passwords needed to be changed.
eBay and PayPal representatives were not immediately available for comment on the notice issued at 1:30 a.m. ET (0630 GMT), which was previously reported by tech blog Engadget.
The message headline was "eBay Inc. To Ask All eBay Users To Change Passwords" but had no other information other than the words "place holder text".
No replacement message was issued on the PayPal site. The link to the notice was replaced with one reading "The message you are trying to access is not available."
Reuters could not immediately verify if the website was hacked or if the message was posted in error.
In April, U.S. web media company AOL Inc urged its tens of millions of email account holders to change their passwords and security questions after a cyber attack compromised about 2 percent of its accounts.
© Thomson Reuters 2014
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