Nat'l Labor Relations Bd. v. City Disposal Systems, Inc.

Holding that a "lone employee's invocation of a right grounded in his collective-bargaining agreement is . . . a concerted activity in a very real sense" because the employee is in effect reminding his employer of the power of the group that brought about the agreement and that could be reharnessed if the employer refuses to respect the employee's objection

Eastex, Inc. v. Nat'l Labor Relations Bd.

Holding that a newsletter that "urg[ed] employees to write their legislators to oppose incorporation of the state 'right-to-work' statute into a revised state constitution," "criticiz[ed] a Presidential veto of an increase in the federal minimum wage and urg[ed] employees to register to vote" was protected concerted activity

Labor Bd. v. Washington Aluminum Co.

Holding that certain employee conduct crosses the line from protected activity to "indefensible" conduct that loses NLRA protections

Wal-Mart Stores, Inc. v. N.L.R.B

Mushroom Transportation Company v. N.L.R.B

In Mushroom Transportation Co. v. NLRB, 330 F.2d 683, 685 (3d Cir. 1964), we held that to qualify as concerted activity "it must appear at the very least that [the conduct] was engaged in with the object of initiating or inducing or preparing for group action or that it had some relation to group action in the interest of the employees."

Owens-Corning Fiberglas Corp. v. N.L.R.B

Noting that, while timing is a factor, "the thrust of Exchange Parts is the condemnation of granting such benefits with the purpose of affecting the outcome of an election"

New River Industries, Inc. v. N.L.R.B

Holding that dress codes are a "condition[] of employment which employees may seek to improve" while receiving the safeguards of the NLRA

Section 157 - Right of employees as to organization, collective bargaining, etc.

Granting employees the right to engage in or refrain from engaging in union activity