Is it usually authorized to run systematic information gathering tools ? I'm talking about tools like nmap, knock, dirb and so on. I'm obviously talking about running them on public websites without consent.

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    Legal questions might be more appropriate on Law.
    – Arminius
    Commented Aug 1, 2017 at 20:26
  • As long as you are not utilizing a website the authorized way, then it is unauthorized. The details regarding "legal" aspects, ie. what the law actually dictates, varies on a lot of factors (your location, location of your target, location through which your data is routed, status of you, your ISP, your target, your target hosting company, etc.) and requires consultation of a lawyer. Commented Aug 1, 2017 at 20:41
  • @Arminius: This question would be off-topic on Law: "Please don't ask questions seeking legal advice on a specific matter.". Either the OP is satisfied with the answer that, unless explicitly stated otherwise, such action is unauthorized, or he must hire a lawyer to study his case in details. Law.SE does not provide free lawyer services, the same way we do not provide free security audit service here. Commented Aug 1, 2017 at 20:45
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    Related: At what point does “hacking” become illegal? (US)
    – Arminius
    Commented Aug 1, 2017 at 21:46
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    @CodyP I was just referring that this question (and questions like it) were off topic due the type of legal question it. I use this meta answer from a moderator as a basis of what is an on/off topic legal question in SE.
    – Bacon Brad
    Commented Aug 1, 2017 at 22:39

1 Answer 1


On a general basis, as long as you are not using a website the authorized way, then you can assume it is unauthorized by default.

Some websites may explicitly authorize the use of automated scanning tools. A classical example of this is Nmap's ScanMe page. In this case the page clearly state the authorization and the associated limitations.

Some general websites also offer bug bounties allowing to some extend the search of vulnerability on their systems. Such website may or may not authorize the use of automated tools, this is usually clearly stated in their bug bounty details.

The "authorized" and "unauthorized" statements however have to be distinguished from the "legal" and "illegal" statements. In some cases, the first ones may have nothing to do with the later ones. In particular, before engaging in any activity which may, even remotely, be considered offensive, ensure that the explicit authorization has been issued by someone in measure to issue it and in full knowledge of any potential consequences (in particular, before allowing such use, the target must check if his hosting company allows it).

Laws controlling such activity are far more complex than one may think, even more when the scanning source and destination (either its HQ or its servers) are located in different jurisdictions. Things may quickly go wrong and out-of-hand. What if the server you were scanning crashed during your scan and the local sysadmin made no backup? Even if your scan may be technically unrelated to the crash, expect to be designated as the main responsible for all the damages and the associated losses.

In doubt, either contact a lawyer before doing anything or abstain.

As a side note, you remain free to scan your own devices on your own network. Simply using virtual machines in your own LAN is usually enough for most personal tests.

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