While well-behaved group minds no doubt are selective of who joins (it is after all rather intimate) and unlikely to assimilate everybody nearby, there might be applications or situations where mental firewalls are down and brains easily form group intellects. Maybe the people in the icon should all be raising their hands in the same way, but this is the clipart I found. "While written as humour about borg-like group think, I find it insightful into group/team behaviour. Particularly the reference to intimacy and the term "metal firewall".
Just for fun, more on these "Warning Signs For Tomorrow" signs here.