Gmail security issue

Security issues in online free world. Are free things really free.

Today I found a major security issue while troubeshooting a gmail issue.
Issue was from last couple of days my brother was getting someone's else emails and the other guy was getting his. All of my brother's private emails and bank emails are freely going on someone else account. I checked all the settings in gmail if auto forward is setup my mistake or something. But nothing like that was set. Problem is they dont even know each other. I got really frustrated seeing this major security issue in gmail. I tried to contact google support but couldn't found any link, phone number. So I mentiomed about this problem in their forum. Still waiting for somebody to respond. Now I am really really scared if this is the way our online privacy is, in online world.

What should I do now????

This is really a major pain. Hoping somehow gmail team look at this post and fix their problem.

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