This is very alarming now, the number of members in telegram group of some ICO are not all investors,
More than 50% of them are just there because of the Airdrop requirements.
Some of those too are bounty hunters, they are just requiring participants to join the ICO group.
Because investors seeing telegram group is the big impact of ICO success.
Not only that, some people (belonging to the team or not) just mass invite random telegram members by the thousands.
No wonder you have 40K members with only 15 people chatting on a regular basis.