A patent suit against Facebook Inc. — the wildly popular social networking site — moved an important step closer to trial last week when a federal judge issued a series of rulings on issues of patent claim construction.

And in a sign that the litigation is getting ugly, the plaintiffs lawyers last week moved for sanctions against Facebook, arguing that it has ignored discovery obligations and "made a mockery of the process for no other reason than to unilaterally obtain that which the court refused to give it — no discovery."