Google’s war against PageRank continues. It appears that Google has now introduced a filter to limit the PageRank queries its data center’s receive.
On November 8, 2007, a good number of PageRank (PR) followers began to notice their favorite PR tools were inoperative and/or returning erroneous results. Initially, there was some speculation that Google would be unleashing another round of penalties against link sellers. Others believed Google was running yet another toolbar export. Everyone was wrong.
Any IP address that queries PageRank from multiple data centers is being blocked after a number of queries. Some are speculating that the queries are capped at 1000 per hour, while my observations lead me to believe it is much lower. Fortunately for some, this filter appears to be only temporary. After a few hours, the temporary block is lifted. One can only speculate if this is the beginning of a more intense offensive against PageRank queries and those that use such tools to validate the sale of links.
The release of this filter is already beginning to ripple through the paid link economy. Link sellers and buyers typically use Online PR tools to verify rank at multiple data centers. Of these Online tools, some offer more advanced features to determine if the rank is authentic or being spoofed by a redirect.
Link sellers and the buyers seeking higher PageRank are not the only ones that benefit from multiple data center tools. There are a number of Websites that have built their visitor base because they provide these tools.
Over the last several months Google has stepped up its enforcement of link sales. Limiting access to its data centers is just another step in reigning in the sub-economy that was created with PageRank.
http://www.articledashboard.com/Article/Google-Blocks-PageRank-Queries/349993