How about this for a crap argument:
“During adolescence and adulthood, the individual tends to develop a more sophisticated identity, often taking on a role as a leader or follower in groups. If an individual develops the feeling that they belong to a group, and they must help the group they are part of, then they develop a sense of community……If community exists, both freedom and security exist as well. The community then takes on a life of its own, as people become free enough to share and secure enough to get along. The sense of connectedness and formation of social networks comprise what has become known as social capital.”

OK so this is an extract from the Wikipedia definition of “community” but it illustrates all that can go wrong when the phrase is bandied around so freely. “If an individual develops the feeling that they belong to a group then….(etc.)” But what if the group is a gang, a criminal enterprise, a secret jihadi group or a fascist party? Does the author really intend these to be evidence of “the development of a sense of community” on a par with joining a local community centre or volunteering with a local self-help group? Of course not.

The next part of the definition reminds me of what used to be known as “the ontological proof of God” (with whom the notion of “community” shares rather too many characteristics!): “If community exists, both freedom and security exist as well”. Why? This is either a disguised tautology (community just IS freedom - which thus says absolutely nothing) or complete and utter nonsense.

How can we distinguish between the strength of the “sense of connectedness” felt by the average member of the Waffen SS and a member of a local scouts group? Both of them feel strongly (often even messianically) that they are part of a group and that they “must help that group” . Of course we can tell the difference by looking at the purposes of the group but not their sense of or degree of commitment or connectedness to their "community" group.
This is why Putnam’s argument starts to unravel – after all it was precisely his argument that areas with high levels of social capital and involvement in associations lead to more democratic, transparent societies. For Putnam social capital = social trust + associational membership. But associations can be bad (the Camorra, the Mafia, Hizbut Tahrir, the BNP etc) as well as good. Furthermore the degree of trust within these communities or associations has nothing to do with their goodness. Bad or corrupt associations can be hugely damaging to societies as Putnam himself points out in the case of Southern Italy with its numerous Mafia-type groups.

Letki and Evans in their recent study "Social trust and responses to political and economic transformation in East-Centre Europe" throw further doubt on the notion that social trust is necessary for political and economic success: "in countries where citizens positively evaluate the workings of democracy and the market and perceive themseleves as influential, they have less need to rely on networks of informal relations with others than do citizens who live in countries where the state and market institutions are largely inefficient". As Coleman pointed out in his "Foundations of Social Theory": trust is an effect rather than a cause - "trust is a result of an institutional setting, not its source".