No, this is not a scam. This offering is by Blockchain Capital who has a long standing in the blockchain industry. Their website is blockchain.capital and the offering website is http://blockchaincapital.tokenhub.com/. You should also review the press-releases on the offering, including industry figures who are investors and advisors of the offering, as well as news coverage:
http://www.prnewswire.com/news-releases/blockchain-capital-to-raise-its-third-fund-via-a-digital-token-offering-300424587.html?tc=eml_cleartime
http://www.prnewswire.com/news-releases/industry-thought-leaders-invest-with-blockchain-capital-in-its-ground-breaking-ico-300436544.html?tc=eml_cleartime
https://medium.com/@blockchaincap/industry-leaders-join-the-blockchain-capital-ico-f4cc34086c33
https://www.smithandcrown.com/sale/blockchain-capital/
http://www.coindesk.com/blockchain-capital-releases-new-details-ethereum-ico-token/
https://cointelegraph.com/news/10-mln-ico-blockchain-capital-outlines-terms-of-funding-round
http://www.newsbtc.com/2017/04/04/blockchain-capital-releases-offering-memorandum-10-million-digital-token-offering/
http://www.the-blockchain.com/2017/04/04/blockchain-capital-releases-offering-memorandum-10-million-digital-token-offering/

If you read Gleb's messages you will see that he does not have any claims with regards to this offering being scam, but rather targets Argon Group's employees personally for an unknown reason. Argon Group is an advisor and bookrunner of this offering and our website is argongroup.com

All the best