Valve announces an updated Steam Subscriber Agreement, becoming the latest company to attempt to avoid potential class action lawsuits by prohibiting them as a term of service. Here is their explanation of this:

We’re also introducing a new dispute resolution process that will benefit you and Valve. Recently, a number of companies have created similar provisions which have generated lots of discussion from customers and communities, and we’ve been following these discussions closely. On Steam, whenever a customer is unhappy with any transaction, our first goal is to resolve things as quickly as possible through the normal customer support process. However in those instances in which we can't resolve a dispute, we've outlined a new required process whereby we agree to use arbitration or small claims court to resolve the dispute. In the arbitration process, Valve will reimburse your costs of the arbitration for claims under a certain amount. Reimbursement by Valve is provided regardless of the arbitrator’s decision, provided that the arbitrator does not determine the claim to be frivolous or the costs unreasonable.

Most significant to the new dispute resolution terms is that customers may now only bring individual claims, not class action claims. We considered this change very carefully. It’s clear to us that in some situations, class actions have real benefits to customers. In far too many cases however, class actions don’t provide any real benefit to users and instead impose unnecessary expense and delay, and are often designed to benefit the class action lawyers who craft and litigate these claims. Class actions like these do not benefit us or our communities. We think this new dispute resolution process is faster and better for you and Valve while avoiding unnecessary costs, and that it will therefore benefit the community as a whole.