Google has been sued again over click-fraud, with a new class-action lawsuit due to be certified in Pennsylvania.

Attorney Samuel Lassoff is both plaintiff and the lead attorney in the case, and claims to have suffered $1,000-worth of click-fraud involving two websites he has for a marketing and reseller business between October 2005 and February 2006.

Lassoff is seeking to have a judge certify his suit for class-action status for residents in Pennsylvania and New Jersey who also think they are paying Google more for online advertising than they should be, due to click-fraud.

Lassoff's complaint was presented to Google on Monday but other parties cannot join until a judge certifies it as an official class-action suit.

Click-fraud occurs when someone clicks on a pay-per-click ad with a malicious intent. For example, a company official may click on competitors' ads to increase their ad spending, which is what Lassoff believed happened in his case.

Another example of click-fraud is a publisher clicking on his website's ads to increase his commissions. Estimates about click-fraud incidence vary, but some place it is as high as 20 percent of all clicks.

Lassoff said he contacted Google about five times through e-mail and phonecalls to report what he believed was click-fraud, when he saw his advertising bills with the company spike while sales remained the same.

He received no response from Google, "not even an e-mail". Lassoff said his case and others like it are ways customers of multi-billion dollar corporations can police them and help prevent them from committing fraudulent activity.

"These companies, left unchecked, become Enron," Lassoff said. "I'm just going to be a part of that. I'm going to help keep that in check."

Google agreed to a $90 million settlement in a class-action click-fraud lawsuit filed in Arkansas. Other companies such as Yahoo that sell online ads also have also been embroiled in click-fraud suits.