Bitconnect (BCC)
BitConnect was widely regarded as a scam and a ponzi scheme, but despite this, some very effective marketing led to the project gaining a very large market capitalization by early 2018. However, in January of 2018, the BitConnect organization suddenly "refunded everyone" by releasing all of the Bitconnect coins to users simultaneously (instead of releasing the Bitcoin or cash that was used to buy the BitConnect coins). The market immediately collapsed over the next several hours, with the coins dropping from over $400 apiece at their high to less than $20 apiece. Although these coins still trade, they're essentially worthless and investors are warned to stay away from the project. Multiple governments have issued warnings. It appears that all the assets of the organization have been seized by the courts effective February of 2018.
Criticisms, Caveats, and Competitors
A huge number of red flags related to this project were obvious to anyone who took the time to do proper due diligence. Unfortunately, "investors" still lost billions of dollars when the price collapsed.
Additional Resources
The project's main website: https://bitconnect.co
Link to Wikipedia Page: https://en.wikipedia.org/wiki/Bitconnect
Link to Reddit Commentary: https://www.reddit.com/r/CryptoCurrency/comments/769f9n/scam_bitconnect_is_a_giant_14b_pyramid_scheme
Link to Twitter account: https://twitter.com/bitconnect
Link to Team information: N/A
Link to data on Live Coin Watch: N/A (because it's a ponzi scheme and a scam)
Whitepaper: N/A (of course not, it's a scam)