What is Fusion GPS?

Daily Mail: Fusion GPS is founded by Tom Catan, Glenn Simpson, and Peter Fritsch

Fusion GPS is an opposition research/espionage firm, mostly used to attack Republicans and conservative groups. They aren't lawyers (so no privilege), they aren't even journalists (anymore).  They are investigators hired privately to dredge up sleaze (or as is contended by some make it up).

Why aren't Republicans more aggressive in subpoenaing Fusion GPS? It is not just Trump. Fusion GPS was hired by Planned Parenthood to go after the people who did the undercover videos. Here's a bombshell that PJ Media reported: Fusion GPS allegedly also worked for Vladimir Putin.

Fusion GPS was behind the Fake News pee dossier that got John McCain all excited

Update: EBL: Turns out, Hillary Clinton paid Fusion GPS

True

EBL: Fusion GPS was in on this

Hot Air: Fusion GPS, Manafort, and FBI

AoSHQ: Media now covering up Fusion GPS

Powerline: Fusion GPS and Stand by your Awan

Circa: Fusion GPS and the Don Jr. meeting and FBI leaking

The Federalist: Americans need to know more about Fusion GPS

Daily Caller: Why's Fusion GPS getting a pass?, Highly paid smear merchants, pleading the 5th

Wombat: American Thinker: Wasserman-Schultz Subverted Democracy, Shark Tank: Fired Dem House IT Aide Has Connections To “Hezbollah-Like” Character, Mark Steyn: The Democrats’ Bet Pays Off, also, Light My Fire

Instapundit: Fusion GPS and its Russian Connections, Roger Simon: Mueller looks ridiculous, Meanwhile, this looks suspicious, Russians playing both sides, Democrats really want to divert attention, nothing to hide?, shopping, let's investigate this fully, and manufactured fake news