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Snuffing Undisclosed History Sniffing

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The FTC has entered into a settlement with Epic Marketplace and its affiliated companies about Epic’s use of “history sniffing.” That’s the practice of sniffing around computer users’ web browsers to find out whether they’ve visited certain websites.   

Epic tracked peoples’ online activities to be able to deliver advertising targeted to their interests.  According to the FTC complaint, Epic served ads to thousands of popular websites.  And when people visited those sites, the company ran a software code behind the scenes – and unbeknownst to the users -- to check out or “sniff” their browser histories.  Epic and its affiliates were checking to see if the user had been to certain sites, including those related to personal issues like fertility, impotence, menopause, incontinence, disability insurance, credit repair, debt relief, and personal bankruptcy. The FTC alleged that Epic then used the information to determine the kinds of ads to serve to those computer users.  For example, if someone visited webpages dealing with credit repair, Epic might target them with ads relating to bad credit or bankruptcy. 

The FTC’s concern?  Epic didn’t disclose that it was engaging in this practice, so computer users had no way to know that their browsing histories were being sniffed, scrutinized, checked out, or peeked at. 

As part of the settlement, Epic and its affiliates have agreed not to sniff browser histories, and not to misrepresent the extent to which they collect, use, or disclose consumer data.

FTC tech experts say you can avoid browser “sniffing” in three easy steps:

  1. Update your web browsers: Several web browser vendors have fixed the flaw exploited by history sniffing websites in recent versions.  Update your browsers to make sure you’re using the current versions.
  2. Use private browsing mode: Web browsers in private browsing mode don’t store local data, including browsing history.  That makes history sniffing websites unable to collect information about the websites you visit when you’re in private browsing mode.
  3. Delete your browsing history: Web browsers allow you to delete your browsing history.  This removes the data that history sniffing websites tend to query.  

To learn about other ways websites collect, store and share bits of information about your online activities to track your behavior across sites – and what you can do about it – read Cookies: Leaving a Trail on the Web.


Someone have been accessing my browser history, even after I have deleted it.This tells me that Firefox know something about this privacy violation.I sent several emails to Firefox, but the issue is ignored.No direct response from Firefox.I think that Firefox is lying about consumer's protection on the web.I bet you Firefox is getting paid to give up consumers browser history.The strange thing it only happens on my Nexsus7.

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