The number of U.S. government requests for data on Google users for use in criminal investigations rose 29 percent in the last six months, according to data released by the search giant Monday.

U.S. government agencies sent Google 5,590 criminal investigation requests for data on Google users and services from Jan. 1 to June 30, 2011, an average of 31 a day. That’s compared to 4,601 requests from July 1 to Dec. 31, 2010, the company reported Tuesday in an update to its unique transparency tool.

Google says it complied in whole or part with 93% of such requests, which can include court orders, grand jury subpoenas and other legal instruments.

For the first time, Google’s transparency report includes the number of users and accounts affected by such requests — in this case, 11,057.

Read more via U.S. Requests for Google User Data Spikes 29 Percent in Six Months | Threat Level | Wired.com.