January this year Google started censoring various ‘piracy-related’ keywords from two widely-used search services. According to Google, the anti-piracy filter is an attempt to curb online copyright infringement. Although the actual search results are not affected, a look at the search volumes reveals that the number of people searching for the censored keywords has indeed dropped significantly.

Starting a few months ago Google began filtering “piracy-related” terms from its ‘Autocomplete‘ and ‘Instant‘ services. The unpublished blacklist includes “torrent”, “BitTorrent”, “uTorrent” and “MegaUpload” and was updated with the term “Mediafire” last month.

According to Google, the blacklist is an effective tool to curb online piracy, even if the terms themselves are not exclusively linked to copyright infringement.

“While there is no silver bullet for infringement online, this measure is one of several that we have implemented to curb copyright infringement online,” Google spokesman Mistique Cano previously told TorrentFreak.

“This is something we looked at and thought we could make some narrow and relatively easy changes to our Autocomplete algorithm that could make a positive difference,” Cano added.

The question is however, does this filter indeed make a difference?

In the past we’ve pointed out that many people discover piracy-related services based on Google’s suggestions. So, if Google’s censorship attempt would indeed decrease the number of actual searches for the filtered keywords, one could argue that it ‘works.’

To find out what effect the anti-piracy filter has had we decided to take a look at Google’s own search trends, and the results are quite astonishing.

Below are the search trend graphs for several forbidden keywords and all show a massive drop in search volume after the anti-piracy filter was implemented in January.

BitTorrent Searches on Google

The graph above reveals that searches for BitTorrent quickly dropped by half, and as of today it remains that way. The graph below shows that a similar pattern can be observed for MegaUpload searches, which had been rising month after month until Google put it on its blacklist.

Megaupload Searches on Google

These search trends are the same for pretty much all the censored keywords. Even searches for the popular BitTorrent client uTorrent dropped to the lowest volume since 2006 after the filter was installed.

Below is the graph for Mediafire searches, one of the latest keywords that was added to the blocklist at the end of April.

Mediafire Searches on Google

Of course the drop in search volume doesn’t mean that there’s a significant drop in actual piracy rates, but the patterns above are surprising to say the least.

Although we had predicted a slight drop in search traffic because of the anti-piracy filter, we never expected it to have this much of an impact. All the more reason for the copyright lobby to suggest banning even more keywords.

While the copyright lobby will count this outcome as a win, the arbitrary filters are not necessarily in the best interests of the Internet as a whole. Google’s lack of transparency about the list of censored keywords and the fact that dictionary words such as ‘torrent’ and company names such as ‘RapidShare’ are included is a worrying development, to say the least.