International hacking collective Anonymous declared war this weekend on ISIS, the extremist militant group that claimed responsibility for the attacks in Paris on November 13 which killed 129 people and left another approximately 350 injured.

In a video released Saturday, a French-speaking member of Anonymous warns ISIS to "expect numerous cyber attacks." Here's the video in question:

But what are the "cyberattacks" in question? What kind of damage can an online force do to an organization it wants to attack? Since the Anonymous video doesn't spell it out, we've gathered up some common tactics used by the group in the past, as well as those used by other major hacker collectives.

Release of private information: retrieval and dissemination of information considered private by ISIS.

Perhaps most impactful of all, Anonymous could outright access the private networks of ISIS and disseminate battle plans, operative names, and countless other pieces of vital information that assists in military action. There's no doubt that world governments are already attempting this themselves, though a hacking collective with a bone to pick may apply methods that are outside of what world governments (and international laws) consider respectable behavior.

"Doxxing" members: revealing personal, private information about members of ISIS.

Another popular attack method used by hacking collectives is "doxxing": the act of releasing personal, private information of specific people, often private citizens. In the case of a group like ISIS, this tactic could be used to expose the personal information of those involved in terrorist activity. This is the kind of information-based warfare that hacking collectives specialize in, which has ripple effects beyond the act itself. 

Information obtained from "doxxing" is often distributed via anonymous, publicly accessible channels like the website Pastebin, or internet forums like 4chan.

"DDoS" attacks: flooding servers with information requests.

A "DDoS" attack is a way of flooding a computer system with far more requests for information than it can handle, thus shutting it down altogether. The acronym's definition goes a long way in describing what it does: "distributed denial-of-service." 

Hackers, employing massive quantities of "virtual" machines — programs acting as full-on computers — request data en masse from a network. When that network is overrun with requests, it shuts down, making it unusable for everyone. 

Anonymous has successfully used this method in the past for shutting down the computer networks of companies or organizations it deems fit for attack, from The Church of Scientology to the municipal computer system of Ferguson, Missouri (in the wake of the shooting death of Michael Brown).

Hack accounts: Take over social media accounts used by ISIS.

This one may be the most obvious weapon in a hacker collective's arsenal: outright hacking of social media accounts. There are a variety of ways that hackers can take over social media accounts, from social engineering (calling Twitter/Facebook/etc. and pretending to be the account's owner) to side doors (using password retrieval of separate, connected accounts to access social media accounts). 

Since ISIS is notorious for using social media to recruit new members, this is a likely course of action for Anonymous.

"Google Bomb" / "Googlewashing" searchable terms with links to anti-ISIS websites.

Ever try searching former Pennsylvania Senator Rick Santorum's last name on Google? Go right ahead. We'll wait.

Notice that the first thing that comes up isn't Rick Santorum's Wikipedia entry, or his personal website, but a page explaining the neologism behind the word that was once his last name. This is the very definition of "Google Bombing" someone: linking en masse to an alternative definition to impact the Google results that come up when someone searches that word. 

Google searches, to some extent, depend on users to define where search terms will send them — more simply, the more websites that return the same information fundamentally alter the search results. If an overwhelming number of websites and users redefine search terms like "ISIS recruiting" (for example), that could seriously impact the group's ability to easily recruit new members.

Prank calls: flood ISIS phone networks with spam phone calls.

Sounds silly, right? How 1990s!

But it was revealed just today that ISIS has a help desk staffed by senior operatives who specialize in encrypted communications. This is exactly the kind of target that a method like mass prank calls (accomplished by digital services — "virtual" phones, if you will) could take down. The concept behind Anonymous' cyberattacks are to disrupt ISIS' ability to operate, thus cripping its ability to perpetrate terrorist acts.