In the ongoing battle between Acer and HP, which has seen brutal attacks from both sides, Acer has made the next move. After petitioning other companies to help them in their legal endeavors, Acer has filed various counterclaims against HP. The claims assert that HP did the very thing they accused Acer of doing - infringing on Acer patents.
Obviously Acer is seeking to protect their growing (but hotly contested) market share and secure their position as the number three vendor worldwide. HP hasn't commented on the situation, but it seems unlikely that the fire between these two giants will die down anytime soon.