When using linux or OSX your SVN credentials are saved under your user profile. 

This happens when you use a IDE or using svn from commandline.

This message is shown then:

-----------------------------------------------------------------------
ATTENTION!  Your password for authentication realm:

   <https://domain.tld> Staff only

can only be stored to disk unencrypted!  You are advised to configure
your system so that Subversion can store passwords encrypted, if
possible.  See the documentation for details.

You can avoid future appearances of this warning by setting the value
of the 'store-plaintext-passwords' option to either 'yes' or 'no' in
'/home/gokhan/.subversion/servers'.
-----------------------------------------------------------------------
Store password unencrypted (yes/no)? yes

Like it says, SVN stores your username and password in plain-text inside your user profile.

To remove all stored SVN username and passwords:

rm ~/.subversion/auth/svn.simple/*

The contents of a credential file looks like this:

K 8
passtype
V 6
simple
K 8
password
V 7
<mypassword>
K 15
svn:realmstring
V 41
<https://domain.tld> Staff only
K 8
username
V 6
<myusername>
END