That was a business, not a group of friends. Google knows darn well they can't sue an individual for clicking on ads. However, they can sue a company. Why? Because companies are open to any lawsuit imaginable. Also, isn't it interesting Google didn't sue those 50 people individually? They only went after the company.
In any case, it's still not illegal. Meaning, you will not go to jail, and a criminal background check will not come back with a "Violated Google's TOS" on a routine traffic stop by a police officer.
This is not a law which is enforceable by state or federal laws. It's a violation of Google's own TOS. Google has a right to enforce their TOS, and sue those who violate it.
[edited by: makes_a_little_sense at 12:52 am (utc) on Sep. 18, 2005]