To send us any contributions you can use this form, ideally over Tor Browser, but please beware that even that won't ensure absolute security
The best way might be to send an encrypted email, alternatively we recommend using a throwaway adress like trash-mail from Tor Browser and in the best case from a Tails Stick and write us to rigaerstrasse@riseup.net
Please ensure that any files like photos, videos, ect areanonymized before you upload them anywhere. On a Linux machine, a Tails Stick, ect this is easily done with the MAT tool.
For bigger Files upto 50mb you can also use share.riseup to upload them and send us the link.
We won't publish anything without going over it to check that no Metadata is attached, but it's in your best interest to destroy it before the files leave you