I think most want you or require you to keep it there. I always take it off though. If I can't take it out without it crashing the theme I just won't use that theme.

how do you got it? is it a custom made theme

no it not custom but its a premium theme i bought for 80 dollars. i asked the people on their forum and 1 person said it was ok but i wanted to check here also.

Pretty sure you can do whatever you want with it. Its probably just like one of those standard things that comes with the theme, but if you paid $80 I would hope there were no limits on things like that. I would change or remove it.

Remove it.

Just go to the 'Appearance' > 'Editor' tab in your Wordpress dashboard.

Search for the file called footer.php and edit it. Search the code for the copyright info and once you find it, either delete it or edit the text to whatever you want.

It's no doubt that you use theme from theme framework. As I knew, most paid frameworks out there are not restricted to remove the footer copyright texts.

Therefore, remove or change it the way you want. It could be change in theme setting, functions, or footer file depend on the frameworks.

Once you buy a theme its yours and you can edit and customize it as you please.