Yahoo is claiming Facebook bought eight of the ten patents that it used to counter-sue in the continuing war between the two internet giants. In a filing to a federal court, Yahoo is asking the judge to throw out the patents that were purchased after Yahoo initially filed suit, PCWorld is reporting.

Yahoo drew first blood in this battle, filing a suit that claimed Facebook infringed on ten of its patents. Many people speculated on the timing of the suit, saying Yahoo was just trying to get their hands on IPO money. Last week they added to the list by filing two more.

Facebook fought back with a countersuit earlier this month, claiming Yahoo violated ten of their patents.

Yahoo is now saying most of those patents should not be submissible, as they were purchased after Yahoo had already filed suit. They claim Facebook bought the patents for the sole purpose of a countersuit against them.

The patents in question were acquired by Facebook from patent firms IPG Electronics 503 and Right Point, Cheah Intellectual Property Licensing, and the New York University intellectual licensing department, according to the Yahoo filing.

They also say Facebook purchased and asserted patents “tainted by inequitable conduct”. According to the filing Facebook intentionally failed to name the known inventor and added new information to existing patents.

Facebook recently purchased 750 patents from IBM to pad its portfolio ahead of its upcoming IPO. They have also agreed to buy patents Microsoft is to acquire from the $1 billion deal to purchase AOL.

Patent purchases are now standard procedure in today’s sue-happy tech culture. Often, companies beef up their patent portfolios in order to sue or defend against litigation. Insiders have equated it to the nuclear arms race of the cold war.

Only this time the bomb has already gone off. I think we are going to see a lot more back and forth before this thing is finally resolved.

Below is Yahoo’s filing of the two additional patent claims from last week.

One is for a “system and method to determine the validity of and interaction on a network” and another is for a “system and method allowing advertisers to manage search listings in a pay for placement search system using grouping.”

Does that sound ambiguous enough for you? Yahoo might as well throw there whole portfolio at them. Facebook encompasses so many facets of programming, advertising, and media, any number of patents could be construed to reflect what Facebook does.

Yahoo reply to Facebook counterclaims