Lives in today's large cities can develop along huge numbers of various scenarios. Completely different are, however, the scenarios adopted by the people of success or the people from the social margin: the unemployed, the homeless, or youth without prospects. Excluded communities perceive the city in a unique manner, and they identify themselves with the city. Specific "cities in cities" develop. They are populated by the people who are unable to use fully the achievements of the present-day civilisation. The city areas where such problems concentrate especially are large housing estates. The process of decreasing positive social identification is accompanied by the processes of growing "claimant" identification. Instead of "neighbourhood individuals," groups representing youth subcultures appear. Their identification develops by denying the existing social and spatial reality. Such negation proceeds from verbal criticism to graffiti to vandalism. The term of "blockers" signifies rebels against the helplessness of life in large-panel housing estates. The "blockers" claim the communal space: staircases, corridors and building surroundings. In extreme cases, crime and terror prevail at housing estates. A method of combating the subcultures that blow up housing estates from inside may be to develop social integration centres by grassroot activities and self-organisation of tenants. Such centres would work for discharging frustrations and generating social expression. Thus, "cities of social expression" could be created within the "cities of frustration." The centres would consist of the following, e.g.: 1. Small sports facilities: fenced playgrounds, gymnasiums, or fitness clubs. 2. Gathering places, or warehouses. 3. "Graffiti Zones" for legal art (e.g. walls, portions of building walls, or screens). 4. "Expression Zones": separate locations for playing (loud) music (even underground facilities), designed for noisy events that are nightmares for housing estates. 5. Unique elements, e.g. facilities for extreme sports, climbing walls, skaters' rings etc.