1. If you get sued and don't show up, the judge might or might not enter a default judgment. Think of a lawsuit as a road rally. The plaintiff has to hit a number of checkpoints. In federal court, one of the first checkpoints is that the complaint---that is, the plaintiff's formal statement of its claim---must allege enough facts to set out a plausible case entitling the plaintiff to relief. (This is the Twombly/Iqbal standard established by the Supreme Court a couple of years ago.) Even if the defendant doesn't show up, usually the judge and his or her law clerk will still read the complaint, to see if it passes the smell test, before granting a default judgment.
2. They can sue you for buying a router, but under section 2-312(2) and (3) of the Uniform Commercial Code [1], absent a proper warranty disclaimer you would normally be able to pass the buck to the seller, by filing a cross-claim for breach of the implied warranty of noninfringement. Of course, that too would require paying a lawyer, unless the seller stepped up and voluntarily assumed the defense of the infringement suit (which is not uncommon; vendors want to stay on customers' good side).
1. If you get sued and don't show up, the judge might or might not enter a default judgment. Think of a lawsuit as a road rally. The plaintiff has to hit a number of checkpoints. In federal court, one of the first checkpoints is that the complaint---that is, the plaintiff's formal statement of its claim---must allege enough facts to set out a plausible case entitling the plaintiff to relief. (This is the Twombly/Iqbal standard established by the Supreme Court a couple of years ago.) Even if the defendant doesn't show up, usually the judge and his or her law clerk will still read the complaint, to see if it passes the smell test, before granting a default judgment.
2. They can sue you for buying a router, but under section 2-312(2) and (3) of the Uniform Commercial Code [1], absent a proper warranty disclaimer you would normally be able to pass the buck to the seller, by filing a cross-claim for breach of the implied warranty of noninfringement. Of course, that too would require paying a lawyer, unless the seller stepped up and voluntarily assumed the defense of the infringement suit (which is not uncommon; vendors want to stay on customers' good side).
[1] http://www.law.cornell.edu/ucc/2/article2.htm#s2-312