Wikipedia:How to deal with vandalism

Wikipedia contributors use the term "vandalism" to refer to changes which are intentionally unconstructive. Such changes may be removal of useful content, addition of nonsense, malicious code or deliberate introduction of factual errors. Vandalism should be removed when found, as it makes articles unhelpful to readers. The problem is that "locking" (using basic term for new people) the pages would lead to lesser contributions and act as a barrier on free speech but not locking the page could always lead to vandalism. Finding a balance, a place in the middle, has always been tough.

Reverting changes
Usually, vandalism can be removed by restoring an older version of the page without the unconstructive changes.

To do this, first click the "history" link at the top of the page to view the page history. Use the "cur" and "prev" links on the left to find which revision(s) introduced the vandalism. Often only one revision will be responsible. If so:


 * Click the "undo" link next to that revision.
 * You will be shown the effect of reversing the revision; if it is correct, click "Publish changes".

Sometimes several revisions introduce vandalism. If so:


 * Click on the timestamp of the last good revision.
 * Click the "edit this page" link at the top of the page.
 * You will be notified that you are editing an old version. Leave the page content as it is, enter an edit summary along the lines of "revert vandalism" and click "Publish changes".

Be careful not to remove useful contributions in the process.

If vandalism and useful contributions are mixed together over several revisions, you will have to remove the vandalism manually.

Manually removing vandalism
Merely removing unconstructive content from the page is not always sufficient, as useful content may have been removed as well. To see what needs to be changed, view the page history, compare the current version of the page to an older revision that is free of vandalism using the "Compare versions" button. This may show both vandalism and useful changes, especially changes by automated processes that do not know how to fix vandalism themselves. Use this as a guide to what needs to be reversed in your edit; use an edit summary along the lines of "revert vandalism".

Warning contributors
Contributors who repeatedly vandalise pages should be warned that this is unacceptable, and if they persist, ultimately blocked from editing altogether by an administrator. Follow the "talk" link next to their name in the page history to go to their discussion page, and click the "new section" link to add a message. There are various pre-defined warning messages that you can use, listed here.

Reporting vandalism
If a contributor continues to vandalise pages despite being warned repeatedly, use the vandalism reporting page to bring this to the attention of administrators.

If an article is subject to repeated vandalism from different users within a short space of time, administrators will sometimes temporarily protect the page, so that it can only be edited by established contributors. This won't be done if the vandalism is all the work of one user, as it is better to deal with that user directly and leave the page open to editing by others. Use the protection request page to ask for this.

Dealing with vandalism more efficiently
If you frequently find yourself dealing with vandalism, there are various tools available to help with this. At any given time there are usually several contributors checking recent edits for vandalism; these tools are of most use to them. There is a list of such tools here.