I'm pretty damn sure there's no law that prevents Steam taking all your toys away and telling you to suck it- even if you've not done anything wrong (although certainly if you have). I guarantee that if you reread the terms of service you agreed to when you signed up to Steam you more or less sign away control over any games you purchase or activate through the service to basically being under their control.
aaaanyway, yeah it's very unlikely they're gonna start doing total lock-outs for the odd drophack. VAC bans are probably on the table for repeat offenders though.
Proof? Or I call bullshit, about the part you said "even if you have done nothing wrong". There's no way Steam can make you agree to such terms and conditions. See below, it states that if you cheat, it can ban your account, but that's all.
I acknowledge that all the software and subscriptions are owned by Valve, but that software and subscriptions are subject to copyright and other applicable Laws.
TLDR;
Steam/Valve can not and will not shut your account down for no reason, however, if you cheat or break their terms and conditions they can shut down your entire account and/or ban you from certain multi-player game/s you cheated in, which is far more likely.
4. ONLINE CONDUCT, CHEATING AND ILLEGAL BEHAVIOR
You agree that you will be personally responsible for the use of your Account and for all of the communication and activity on Steam that results from use of your Account. Your online conduct and interaction with other Subscribers should be guided by common sense and basic etiquette. Specific requirements may also be found in the Steam Online Conduct rules at
http://steampowered.com/index.php?area=online_conduct, other Rules of Use, the Subscription Terms, or in terms of use imposed by third parties who host particular games or other services.
Steam and the Software may include functionality designed to identify software or hardware processes or functionality (“Cheats”) that may give a player an unfair competitive advantage when playing multiplayer versions of any Software or modifications thereof. You agree that you will not create or assist third parties in any way to create Cheats. You agree that you will not directly or indirectly disable, circumvent, or otherwise interfere with the operation of software designed to prevent or report the use of Cheats. You acknowledge and agree that either Valve or any online multiplayer host may refuse to allow you to participate in certain online multiplayer games if you use Cheats in connection with Steam or the Software. Further, you acknowledge and agree that an online multiplayer host may report your use of Cheats to Valve, and Valve may communicate your history of use of Cheats to other online multiplayer hosts for Software. Valve may terminate your Account or a particular Subscription for any conduct or activity that Valve believes is illegal, constitutes a Cheat, or which otherwise negatively affects the enjoyment of Steam by other Subscribers. You acknowledge that Valve is not required to provide you notice before terminating your Subscriptions(s) and/or Account, but it may choose to do so.
You may not use Cheats, automation software (bots), mods, hacks, or any other unauthorized third-party software, to modify or automate any Subscription Marketplace process.
E. Ownership.
All title, ownership rights and intellectual property rights in and to the Software and any and all copies thereof, are owned by Valve US and/or its or its affiliates’ licensors. All rights are reserved, except as expressly stated herein. The Software is protected by copyright laws, international copyright treaties and conventions and other laws. The Software contains certain licensed materials and Valve’s and its affiliates’ licensors may protect their rights in the event of any violation of this Agreement.
2. LICENSES
A. License Terms.
Steam and your Subscription(s) require the automatic download and installation of Software onto your computer. Valve hereby grants, and you accept, a limited, terminable, non-exclusive license and right to use the Software for your personal use in accordance with this Agreement, including the Subscription Terms. The Software is licensed, not sold. Your license confers no title or ownership in the Software. To make use of the Software, you must have a Steam Account and you may be required to be running the Steam client and maintaining a connection to the Internet.
You understand that for reasons that include, without limitation, system security, stability, and multiplayer interoperability, Steam may need to automatically update, pre-load, create new versions of or otherwise enhance the Software and accordingly, the system requirements to use the Software may change over time. You understand that this Agreement (including applicable Subscription Terms) do not entitle you to future updates, new versions or other enhancements of the Software associated with a particular Subscription, although Valve may choose to provide such updates, etc. in its sole discretion.