Picketing is a form of protest in which people (called pickets or picketers) congregate outside a place of work or location where an event is taking place. Often, this is done in an attempt to dissuade others from going in ("crossing the picket line"), but it can also be done to draw public attention to a cause. Picketers normally endeavor to be non-violent. It can have a number of aims, but is generally to put pressure on the party targeted to meet particular demands or cease operations. This pressure is achieved by harming the business through loss of customers and negative publicity, or by discouraging or preventing workers or customers from entering the site and thereby preventing the business from operating normally. Picketing is a common tactic used by trade unions during strikes, who will try to prevent dissident members of the union, members of other unions and non-unionised workers from working. Those who cross the picket line and work despite the strike are known pejoratively as scabs. Types of picket Informational picketing is the legal name given to awareness-raising picketing. It, per Merriam-Webster's Dictionary of Law, entails picketing by a group, typically a labour or trade union, which inform the public about a cause of its concern. In almost all cases this is a disliked policy or practice of the business or organisation. It is a popular picketing technique for nurses to use outside of healthcare facilities. For example, on April 5, 2006, nurses of the UMass Memorial Medical Center (UMMHC) took part in two separate such events to protect the quality of their nursing program. Informational picketing was used to gain public support and promote further bargaining with management. It may also be a spur or auxiliary to a petition to government to seek regulatory intervention, reliefs, dispensations or funds. A mass picket is an attempt to bring as many people as possible to a picket line to demonstrate support for the cause. It is primarily used when only one workplace is being picketed or for a symbolically or practically important workplace. Due to the numbers involved, and depending on behaviors, it may turn into an unlawful blockade such as a right of way obstruction, or aggravated trespass (denial of access). Secondary picketing is of any external entity economically connected to the main business subject to the workers' action. Thus it includes against suppliers on which the picketed