The seemingly endless litigation tech companies engage in just took a very serious tone. While suing over iPhone designs or WiFi radios is important, even interesting, it’s not necessarily crucial to the way a company does business. A new lawsuit filed against Google threatens the absolute core of what Google does, and it could get ugly.

Rockstar — a company owned by heavy hitters like Apple, Microsoft, Blackberry, Ericsson and Sony — has filed suit against Google. The lawsuit, filed in Texas federal court, claims Google infringed on several patents that have to do with search results and advertising. More to the point, the lawsuit claims Google is infringing on patents by using search results to return targeted advertising.

We see the action daily, even if we choose not to pay it any mind. You search for something like pocket knives, then you visit some random website. Lo and behold, there’s an ad for pocket knives — even if the site has nothing to do with knives, or camping, or anything that could possibly be related to your search. That’s the most glaring example of how your search results are targeted to advertising, and it’s a massive part of Google’s revenue stream.

These patents are all from a company named Nortel, which Google tried to purchase when the company went bankrupt in 2011. Google’s initial offer for $900 million found it’s way to $4.4 billion through a bidding war with — you guessed it — Rockstar. Rockstar ended up with Nortel’s patents, and Google ended up purchasing Motorola shortly thereafter, in what many felt was a patent grab. Now, Rockstar is aiming their patent cannons at Google, and this one will be war.