Picketing, a term used to describe a practice resorted to by workmen engaged in trade disputes, of placing one or more men near the works of the employer with whom the dispute is pending, with the object of drawing off his hands or acquiring information useful for the purposes of the dispute. In England, under the Conspiracy and Protection of Property Act 1875, it is an offence wrongfully and without legal authority to watch or beset the house or place where another resides or works, or carries on business or happens to be, or the approach to such house or place, if the object of the watching, &c., is to compel the person watched, &c., to abstain from doing or to do an act which he is legally entitled to do or to abstain from doing (§ 7). The definition of the offence was qualified by a proviso excluding from punishment those who attend at or near a house or place merely to obtain or communicate information, in other words what is termed peaceful picketing, without intimidation, molestation or direct efforts to influence the course of a trade dispute. This enactment led to a great deal of litigation between trade unions and employers; and trade unions were in some instances restrained by injunction from picketing the works of employers, The decisions of the courts upon this subject met with severe criticism from the leaders of trade unions, and by the Trades Disputes Act 1906 the proviso above quoted was repealed, and it was declared lawful for one or more persons acting for themselves or for a trade union or for an individual employer to attend at or near a house, &c., "if the attendance is merely for the purpose of peacefully obtaining or communicating information or of peacefully persuading any person to work or abstain from working." The exact effect of this change in the law has not yet been determined by the courts, but during the Belfast carters' strike of 1907 serious riots ensued upon the efforts of the authorities to counteract the interference with lawful business caused by free use of picketing. The change in the law is supplemented by provisions forbidding actions against trade unions in respect of any tortious acts alleged to have been committed by or on behalf of the union.