I have downloaded quite some Tumblr videos, both cat videos, funny clips, porn. I downloaded them manually, you can save them with right click and save-as with right method - no download program used. I have old external hard drive where I keep them, downloaded both in Mac and in Windows. After clean install (due to technical issues not malware), I was going to put my collection back to fresh Mac, but heard these videos could contain malicious code/trojans/malware? Haven't done it for a month now - likely never will again just in case - but it would be pity to delete them all so... do I have to for security reasons? My question is - how likely could videos downloaded from Tumblr be malicious? After all, it is one platform for many different blogs - cat videos, funny clips, porn - they are all uploaded to same server so how likely is they can be infected by a) uploader b) tumblr itself?