Error Message: "can't process your request right now..."

Weird error message.

[WeirdCode]

For a certain search (search string is saved here and can be sent to anyone who is interested) I got this message from Google:

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Google Error

We're sorry...
... but we can't process your request right now. A computer virus or spyware application is sending us automated requests, and it appears that your computer or network has been infected.

We'll restore your access as quickly as possible, so try again soon. In the meantime, you might want to run a virus checker or spyware remover to make sure that your computer is free of viruses and other spurious software.

We apologize for the inconvenience, and hope we'll see you again on Google.
===================

Furthermore, G's title tag says "403 Forbidden". Has anyone encountered something like that before?