Google, Microsoft sued over map technology
Visitors interact with Bing Maps at Microsoft booth during the 2010 International CES in Las Vegas Reuters

Sometimes, competition among businesses is petty, dirty, and illegal.

Over the last few months, unscrupulous business owners have taken their dirty tactics to Google Maps, reported NYTimes.

These users (or the black hat marketing firms they hired) went on Google Places - which contains listings of the businesses seen on Google Maps - and spam the this place is permanently closed button.

If enough users do it, Google marks the victim business as Reported to be closed. Then, pending a review and approval, the victim's mark becomes This place is permanently closed.

Google said it does its best to verify and review the closed claims before marking a place permanently closed.

Still, NYTimes reported at least three cases of operating businesses that were fraudulently flagged Reported to be closed by spammers and marked This place is permanently closed by Google.

For weeks, our bookings for September have been far lower than normal and we were wondering why, said one of them.

I have no doubt that a lot of people running up and down that highway just skipped us, said another, whose business is located near a highway.

Spamming Google Maps isn't the first time businesses have resorted to black hat techniques to hit at rivals online. Below are three more documented abuses.

Click Fraud

Click Fraud is spam-clicking a competitors' pay-per-click advertising campaign. By doing so, the spammers drive up the cost of advertising for their competitors without giving them real leads and sales.

The issue of click fraud was so prevalent that Google was forced to enact multiple measures to combat it.

Smear Campaigns

Unscrupulous companies either hire black hat marketing firms or have their employees write fake negative reviews about their competitors.

This happens on Web sites like, eBay and Google Places.

Sometimes, big companies even pay PR firms to pitch negative stories against competitors.

Outright Hacking

Sometimes, it's just outright hacking, mostly done with the intent of stealing proprietary information.

This generally happens to larger companies, often at an international level and with foreign government backing.

Dmitri Alperovitch of cyber security firm McAfee, for example, asserted in an August 2011 post that every company in every conceivable industry with significant size and valuable intellectual property and trade secrets has been compromised (or will be shortly).

I divide the entire set of Fortune Global 2000 firms into two categories: those that know they've been compromised and those that don't yet know, he said.