Patent trolls are exploiting a bug in the patent system. They don't buy patents that are actually novel and useful; those are too expensive. Instead, they buy 1

Patent trolls are exploiting a bug in the patent system. They don't buy patents that are actually novel and useful; those are too expensive. Instead, they buy 100s or 1000s of patents that are vague and/or obvious. These are cheap to buy because they don't have much of any value on their own. They bundle dozens of these together, find lists of companies somewhat related and send demand letters to all of them. Simply defending the lawsuit will cost more than they're asking for in the demand letter, so many companies just settle and write a check.