It will be "Stack Overflow" ( rather than stock overflow ).
A "stack" is a "first-in-last-out register" - a sort of memory storage location, and when it overflows, too much information has been "pushed" onto the stack so that it has run out of space for further information - hence the term overflow.
. If you have only noticed it on Tumblr, it is probably a programming fault on the active script on that page. . However, it won't do any harm to clear out your internet history and similar private data incase something redundant is causing the problem.
. Such a clearing of of the "temporary internet data" will most likely delete all cookies, and subsequently you will need to log on, again, to sites that store such data in cookies.
. ..... Sites that you might not normally have to log onto more than once. Hopefully you have noted down all relevant passwords and usernames.
Best wishes - Majikthise. .
ugh i'm so lazy to do that. thank you though.