Infringement could not occur in the course of advertising activities
Aetna, Industrial Indemnity vs. Orange County Superior Court

Insurance Coverage - Advertising Liability - Trademark Infringement
Lebas Fashion Imports of USA v. ITT Hartford Insurance Group

Enumerated Offense of Infringement of Title Does Not Include Patent Infringement
Maxconn Inc. v. Truck Ins. Exchange 99 C.D.O.S. 7738 (Sept. 16, 1999)

Finally. . . Potential Insurance Coverage for Patent Infringement Litigation
Everett Associates, Inc. v. Transcontinental Ins. Co., 57 F.Supp.2d 874

According to one trade association, in 1999, the median estimated cost of a patent infringement action through discovery was about $800,000, and through trial and appeal, approximately $1,500,000.
Some methods used by infringers to undermine patents or plaintiffs include

Insurance Coverage for Intellectual Property Claims
Typically, coverage for intellectual property claims is found under the "advertising injury" coverage afforded under most general liability policies.

Insurer Has No Duty To Defend Patent Infringement As "Advertising Injury"
U.S. Test, Inc. v. NDE Environmental Corp., No. 99-1087 (Fed. Cir. Nov.19, 1999

California Court of Appeals Holds That Patent Infringement Does Not Arise Out Of Enumerated Advertising Injury Offense Of "Infringement of Copyright, Title or Slogan."

Industrial Indemnity Co. v. Apple Computer, Inc.
Many coverage issues still remain unresolved under the advertising injury coverage created by the standard form 1986 policy. This case considers several issues, including a territorial limitation, as well as the scope of infringement of title coverage.

Right to Independent Counsel - Copyright Infringement - Midiman v. Farmers Insurance Company As long as only liability was at issue, there was no actual conflict and no need for Cumis counsel.

It is settled law that except perhaps in unusual circumstances, patent infringement is not covered under CGL policies.  Bank of the West v. Superior Court (1992) 2 Cal.4th 1254; Gitano v. Kemper (1994) 26 Cal.App.4th 49; Aetna v. Superior Court (1993) 19 Cal.App.4th 320; Everest & Jennings v. American Motorists Ins. (9th Cir. 1994) 23 F.3d 226; Intex Plastics v. United Nat. Ins. (9th Cir. 1994) 23 F.3d 254; Iolab v. Seabord Sur. (9th Cir. 1994) 15 F.3d 1500.