From what I've read, the WOT extension has been removed from various official websites (e.g. firefox add-ons page, Chrome's), but has not been actively blocked by firefox for existing users. I would recommend deleting that extension from your webbrowsers.
As far as POP Peeper is concerned -- POP Peeper uses the WOT API directly. Only the domain names are sent to WOT, e.g. if you get a bill from your electric company that includes personal information in the URL:
http://www.test.com/?userid=someone
PP only sends "test.com" to WOT to be verified.
If you wish to disable the WOT plugin in POP Peeper
1) From the main menu, select Tools / Plugins
2) Find "Web of Trust" in the list and uncheck it
If you plan on deleting the plugin, it is recommended that you disable it first so that it will remain disabled if it is unintentionally installed again.
The plugin's filename is:
\POP Peeper\Pro\UrlCheck.dll
I am currently waiting for more information about this issue before making any ultimate decisions. There is only limited chatter from users on the mywot forums, and there has not been any official announcement from WOT yet.
If anyone has any further information, let us know here.