Team Viewer Safe?

I do a lot of upgrades and get a lot of people who want to use team viewer... i just did it for the first time a few days ago and just read a few posts saying don't use it... I'm not giving any of my info to them am i?

 

Teamviewer is great in the sense that you can apply someones Upgrade in a way that they don't need to give you there Username and password and they can see you applying the upgrade, but it's also a danger because they're giving you access to there PC, and you can put Virus' on there, etc.

But generally when you are the one controlling the PC, you're safe.