Over a year after filing a lawsuit alleging infringement of five patents, the plaintiffs decided to voluntarily move to dismiss the case against the defendant with prejudice and proceed against a group of different defendants. After the Court granted that motion the defendant filed a motion to declare the case exceptional pursuant to 35 U.S.C. Section 285 and award defendant its fees and expenses. Parker-Hannifin Corp. v. Seiren Co., C.A. No. 07-104-MPT, Memorandum Opinion (D. Del. Mar. 31, 2009). Magistrate Judge Mary Pat Thynge, citing Judge Farnan’s recent decision in Prism Techs. LLC v. VeriSign, Inc., found that plaintiffs’ analysis of defendant’s product, using an electron micrograph to identify coverage by its patents was a sufficient pre-filing investigation. “Though further investigation could have occurred before filing suit, [plaintiffs’] investigation suggests that its action was neither vexatious or unjustified, and that its assessment of infringement was not manifestly unreasonable.” Id. at 7. Furthermore, seeking dismissal about one year after receiving discovery from defendant was not reckless because “[p]arties should be able to terminate litigation when costs make trial an unattractive remedy or when other litigation strategies develop.” Id. at 8.